Is the Mafia a part of "The Kingdom of God?" I would say no, because the Mafia is inherently sinful.
Is "Civil Government" a part of "The Kingdom of God?" I would say no, for the same reason. "Civil Government" and the Mafia are both rivals to the Kingdom of God. Civil Government is a false god.
Is "The Institutional Church" a part of "The Kingdom of God?"
While the Mafia and "Civil Government" engage in murder and theft -- by definition -- "The Institutional Church" doesn't appear (at first glance) to engage in such overt sin.
I would like to suggest that a closer examination shows that "The Institutional Church" is not even a part of "The Visible Church."
Wikipedia helps distinguish between the "Visible Church" and the "Invisible Church":
The invisible church or church invisible is a theological concept of an "invisible" body of the elect who are known only to God, in contrast to the "visible church"—that is, the institutional body on earth which preaches the gospel and administers the sacraments. Every member of the invisible church is saved, while the visible church contains some individuals who are saved and others who are unsaved. According to this view, Bible passages such as Matthew 7:21-27, Matthew 13:24-30, and Matthew 24:29-51 speak about this distinction.
The concept was insisted upon during the Protestant reformation as a way of distinguishing between the "visible" Roman Catholic Church, which according to the Reformers was corrupt, and those within it who truly believe, as well as true believers within their own denominations. John Calvin described the church invisible as "that which is actually in God's presence, into which no persons are received but those who are children of God by grace of adoption and true members of Christ by sanctification of the Holy Spirit... [He] includes not only the saints presently living on earth, but all the elect from the beginning of the world." He continues in contrasting this church with the church scattered throughout the world. "In this church there is a very large mixture of hypocrites, who have nothing of Christ but the name and outward appearance..." (Institutes 4.1.7)
Pietism later took this a step further, with its formulation of ecclesiolae in ecclesia ("little churches within the church").
The "Invisible Church" is therefore the body of true believers, actually "born again," and the "Visible Church" is the collection of those who profess to be Christians, some sincerely, some hypocritically, some out of self-deception.
Again, Wikipedia:
In Catholic doctrine, the one true Church is the visible society founded by Christ, namely, the Catholic Church under the global jurisdiction of the bishop of Rome.
Protestants have developed a concept of "the visible church" which roughly parallels that of Rome. In an article entitled, The Visible Vs. The Invisible Church, Brian Schwertley writes:
The visible church is set apart from the world by profession as well as its external government, discipline, and ordinances (e.g., the preached word and the sacraments). The members of the visible church have obeyed the outward call of the gospel, professing Christ, submitting to baptism and placing themselves under the preaching and authority of the local church.
In other words, "the visible church" is here identified or equated with "the institutional church" or "the organized church," or "the local church."
R.J. Rushdoony calls this into question.
To define the kingdom of God or the visible church in terms of the institutional church is to take the road to Rome, to drift toward the subordination of every avenue of life to the church. Many Protestants indeed share in this position and view every avenue of life with suspicion apart from ecclesiastical domination. But for us the biblical church, the kingdom of God on earth, is to be identified with the reign of God in the hearts of men wherever they are. Consequently, we must hold that the Christian home is a part of the visible church, as is the Christian school, the Christian state, and the Christian man in his calling, godly men everywhere in their calling serving as priests of the Kingdom of God on earth. The Christian as scientist manifests the activity of the visible church, of the Kingdom of God on earth, in his particular sphere of activity. The Christian farmer, as he subdues the earth and exercises dominion in the name of God is thereby manifesting the activity of the visible church in his particular sphere. Consequently, the Institutional church is definitely not one area above all the other areas of life, but is one aspect of the Kingdom of God on earth among many others. For us, therefore, the Institutional church together with and not above the school, the home, the Christian man in whatever calling or sphere of activity is his, equally represents the Visible church, the Kingdom of God. The Christian school is a part of the visible church, and every school has a responsibility, if it be true to its function, to become a manifestation of the Kingdom. h/t
Rushdoony seems to grant the legitimacy of "the institutional church," through Gary North would say that Rushdoony implicitly denies it. Rushdoony also seems to grant the legitimacy of the concept of "the Christian State." I would say Rushdoony implicitly denies it, but that's another essay.
If any Godly calling, or "lawful calling," is an expression of the "visible church," then we ought to ask whether "the institutional church" is a part of "the visible church." That is, whether someone who holds "office" in "the institutional church" has a legitimate "calling."
The Protestant doctrine of "The Priesthood of All Believers" rests on Biblical teaching that all believers are priests and kings (Revelation 1:6; 5:10; 1 Peter 2:9).
However, I would suggest that no believer has a right to be a "priest" or a "king" in a monopolistic sense that differs from the idea of "The Priesthood of All Believers."
Contrary to the Church of Rome, being a "priest" is not a Godly calling. That is, being an "ordained" priest, in a way that unordained people are not "real" priests, is not a Godly calling. There is only one Priest: Jesus the Anointed. The book of Hebrews asserts this claim against Jewish priests operating in the now-defunct Old Covenant, but the analysis applies to priests in modern religions, including Christian denominations. Anyone claiming to be a "priest" in the "ordained" and "sacramental" sense of the Roman Catholic Church denies the priesthood of Jesus Christ and His once-for-all sacrifice.
Similarly, no man has a "divine right" to be a king. No Christian should "vote" for a creaturely king. Having a "king" in this monopolistic sense is a rejection of God.
Rushdoony mentions the callings of scientist, farmer, homemaker, and educator. These are certainly Godly callings.
He says these callings are expressions of the Kingdom of God on earth. When farmers discharge their calling according to the Law of God, they exercise dominion over the earth (Genesis 1:26-28) and bring the government of Christ to the earth. They are part of "the visible church" on earth. All legitimate businesses are part of "the visible church."
What about being a singer? What about making a living by singing and selling recordings to help people in some way? A Godly calling?
Sure, if the music is Godly.
How about a "conference speaker?" Is traveling from conference to conference giving advice a Godly calling? How about someone who works with "Marriage Encounter" and helps couples strengthen their marriages? A Godly calling?
Sure, if the marriage advice is Godly.
How about someone who helps the poor? Is this a Godly calling?
Everyone should help the poor, but I can't see anything wrong with someone who does it full-time, operating a charity, as a "calling."
Romans 12 and 1 Corinthians 12 speak of a division of labor. Some are hands, some are feet, and together we are the Body of Christ, and The Messiah exercises His Messianic Reign -- the Kingdom of God -- through all His saints as they discharge their various callings. By obeying Christ's commandments in our callings, we create civilization, which is the Kingdom of God, and the salvation most frequently spoken of in the Bible. The "invisible church" -- those who are truly Christ's elect -- manifest the "visible church" by their obedience to Christ in their callings.
Now let's take Rushdoony's insight and answer the question posed at the beginning of this essay.
Is "The Institutional Church" a Part of "The Visible Church?"
According to Schwertley above, the institutional church is something non-ordained people "place themselves under." They "submit" to "the authority of the local church."
Is requiring people to "submit" to your "authority" in "the local church" a Godly calling?
Let's think about the singer, who composes or performs music, recorded or live in a concert, which inspires people to a more effective discharge of their calling. What if a singer quoted Ephesians 5:19 and Colossians 3:16, which command us to "admonish one another with psalms and hymns and spiritual songs," and claimed "apostolic authority" based on these verses, and told people that she had been "ordained" by singers who trace their musical calling back to the Apostles themselves, and that people were required to attend her concerts, and that failure to attend her concerts amounted to "self-excommunication" from the Body of Christ, and failure to attend her concerts had "eternal consequences."
This is guilt manipulation, and is no longer a Godly calling.
How about a popular conference speaker, who says that he has been "ordained" into a long line of traveling conference speakers going back to the Apostles, and that failure to attend his conference is sinful?
This is not a Godly calling anymore. It's laying spiritual burdens on people that are not found in Scripture.
What about the one who "serves" the poor, and claims that failure to tithe to his charity is sinful, and if you don't give, you are stealing from God?
Suddenly, a Godly calling has become as spiritually dangerous as the Judaizers.
"The visible church" in the Roman Catholic sense is "the local church" in the Protestant perspective. It is a group of people who claim "authority" from the Apostles to govern the Body of Christ. "The local church" claims the right to order you to attend "services" at 10:30am on Sunday morning, to listen to their singers and conference speakers. They claim the authority to order you to make charitable contributions to their deacons, before you even think of donating to any other charitable ministry. Gary North, in opposition to Rushdoony, writes:
You are a thief if you do not give ten percent of your net income to your local church. If you give any portion of this required ten percent to any organization except your local church, you are also a thief, unless your church's elders have authorized you to send a portion of your tithe elsewhere.
[A]s ordained agents of God, the ministers of every congregation should preach the tithe, enforce the tithe, and impose penalties on church members who refuse to pay the tithe - as surely as they should report known thieves to the police. They are God's agents....
Men owe God ten percent of any net increase of their income. But which institution lawfully collects the tithe in God's name? The answer today is what it was when Abraham paid his tithe to Melchizedek the priest (Gen. 14:20): the institutional Church. Melchizedek served Abraham bread and wine (v. 18) and blessed Abraham in God's name (v.19). The Church has lawful monopoly claim on the tithe because it has lawful monopoly jurisdiction over the administration of the sacraments. Today, there are parachurch ministries that falsely claim a portion of the tithe. This book presents a theology of the tithe in terms of a theology of the institutional Church. It refutes the arguments that tithing and dominion go together apart from tithing to the institutional Church.
Did Melchizedek circumcise hundreds of domestic apprentices in Abraham's household, or did Abraham do the job himself? Did priests go from house to house officiating over all the Passover meals in Israel?
Years ago, Gary North wrote an essay entitled, "Family Authority and Protestant Sacerdotalism" in the Journal of Christian Reconstruction, Vol. III, No. 2 (1977-78). Download the issue here. He said the Family has the authority to "administer the sacraments."
An employer exercises more spiritual government over his employees five days a week (or could, and should) than "elders" in a "local church" can one day a week.
"The Institutional Church" is not wrong for what it claims to do (teach, help the poor, etc.), it is wrong for claiming a monopoly. The claim of monopoly privilege ("sacerdotalism") turns a legitimate calling in a competitive Free Market into something unScripturally dangerous and spiritually destructive.
Being "The Institutional Church" is not a legitimate calling, and therefore is not a part of "the visible church."
Towards a Non-Monopolist Church
"Brute and isolated factuality does not exist. Every person, thing, or event has in the background a vast complex of causes, influences, conditioning factors, and forces which have produced that person, thing, moment, or event. Its freedom is to be what it is, and what God ordained it to be. Compulsion is that which interferes with the matrix of convergent causes. I am a servant of God, and whatever interferes with my calling, or tries to prevent it, is compulsion to me. I am predestined by God, and therein is my freedom. I am not under nature, nor am I the creator of man. If a tyrant seeks to prevent me or hinder me in my obedience to the Lord, that is compulsion, and it is tyranny. Tyranny means in origin rule apart from God’s law. God’s law, in the form of both predestination and Biblical law, is to me freedom."
~R.J. Rushdoony, Systematic Theology, vol. I, p. 79.