I am curious if "Christian Reconstructionism" and is real and if so, a cult. Some people said that Christian Reconstructionism is the idea of some Christian trying to bring America back to its Christian roots, but they are trying to follow some Old Testament laws. In doing so, some of them will try to criminalize homosexuality and treat non-Chrisitians unfairly. I think some Christians are aware of this movement because they wrote some articles on it. Feel free to correct me if I presented this information inaccurately.
"Cults" are marked by people following a dynamic leader, whose word is held as the ultimate authority. Typically a cult does not survive the death of the leader, though a few have. Just because you disagree with someone's beliefs, it does not automatically make it a cult.
"Christian Reconsructionism" was a fad from the 1990's where people advocated that government should operate under the Old Testament laws. It is misnomer since the Laws of Moses predate Christianity and came to an end when Jesus died on the cross.
"Therefore remember that you, once Gentiles in the flesh -- who are called Uncircumcision by what is called the Circumcision made in the flesh by hands -- that at that time you were without Christ, being aliens from the commonwealth of Israel and strangers from the covenants of promise, having no hope and without God in the world. But now in Christ Jesus you who once were far off have been brought near by the blood of Christ. For He Himself is our peace, who has made both one, and has broken down the middle wall of separation, having abolished in His flesh the enmity, that is, the law of commandments contained in ordinances, so as to create in Himself one new man from the two, thus making peace, and that He might reconcile them both to God in one body through the cross, thereby putting to death the enmity" (Ephesians 2:11-16).
There is nothing "Christian" about living under the Mosaical Law.
It also ignores the fact that the Law of Moses was specifically designed for the Israelites and no other nation. "For what great nation is there that has God so near to it, as the LORD our God is to us, for whatever reason we may call upon Him? And what great nation is there that has such statutes and righteous judgments as are in all this law which I set before you this day?" (Deuteronomy 4:7-8). At its core it required the people to follow God, who was actively involved in the decisions being carried out. But the Israelites failed to keep this law. "Behold, the days are coming, says the LORD, when I will make a new covenant with the house of Israel and with the house of Judah -- not according to the covenant that I made with their fathers in the day that I took them by the hand to lead them out of the land of Egypt, My covenant which they broke, though I was a husband to them, says the LORD" (Jeremiah 31:31-32). What makes people think they can succeed where Israel failed? And do so without God's authorization or backing?
Finally, people who argue this don't want the whole Old Law enforced. They want to skip over parts, such as the requirements for sacrifices and the festivals which require all males to travel to Jerusalem three times a year. "Stand fast therefore in the liberty by which Christ has made us free, and do not be entangled again with a yoke of bondage. Indeed I, Paul, say to you that if you become circumcised, Christ will profit you nothing. And I testify again to every man who becomes circumcised that he is a debtor to keep the whole law. You have become estranged from Christ, you who attempt to be justified by law; you have fallen from grace" (Galatians 5:1-4).
In the early church there were people arguing that Gentile converts were supposed to be taught to follow the Law of Moses. Paul argued against it. "And certain men came down from Judea and taught the brethren, "Unless you are circumcised according to the custom of Moses, you cannot be saved." Therefore, when Paul and Barnabas had no small dissension and dispute with them, they determined that Paul and Barnabas and certain others of them should go up to Jerusalem, to the apostles and elders, about this question" (Acts 15:1-2). When Paul and Barnabas went to Jerusalem to talk about the conversion of Gentiles, they were met with the same assertion: "But some of the sect of the Pharisees who believed rose up, saying, "It is necessary to circumcise them, and to command them to keep the law of Moses"" (Acts 15:5). After the resulting discussion in which Peter proved that God accepted the Gentiles without them becoming Jews, Paul and Barnabas proved that God showed support of the conversion of the Gentiles through the miracles being performed, and James proved that the Law of Moses stated that the Gentiles would be offered salvation, the conclusion was: "They wrote this letter by them: The apostles, the elders, and the brethren, To the brethren who are of the Gentiles in Antioch, Syria, and Cilicia: Greetings. Since we have heard that some who went out from us have troubled you with words, unsettling your souls, saying, "You must be circumcised and keep the law" --to whom we gave no such commandment ..." (Acts 15:23-24). Christians have never been required to keep the Law of Moses.