2 Thessalonians 2:3, Falling away [Gr. apostasia].
Whether the mainstream Western church is apostate or not depends on how define the word “apostate.” The word apostate comes from the biblical Greek apostasia, which literally means “a falling away or defection or forsaking of the truth.” That word is found in only two places in the NT. One place is 2 Thess 2:3. What is Paul telling us that people are falling away from? From the truth (see verses 10, 12, 13). What is the truth? Yeshua is the truth (John 14:6), so is the Word of Elohim (John 17:17), and so is the Torah (Ps 119:141, 152), and finally, to unite everything together, Yeshua is the Torah-Word of Elohim in flesh form (John 1:1, 14).
The other place that apostasia is found in the NT is Acts 21:21 where some Jews were falsely accusing Paul of forsaking or falling away from the Torah—an accusation he vigorously opposed, even to his own personal detriment. In defending himself against this lie, he eventually was arrested and sent to Rome for trial, which eventually led to his martyrdom. Ironically and sadly, the mainstream Christian church, to this day, believes the lies of Paul’s false accusers—that he was forsaking or abandoning or falling away (apostasia) from the truth of the law. So now to answer your question specifically: Is the American church apostate? The answer is yes and no. To the degree that the church, any church, or person, or denomination or whatever doesn’t have the truth (as the Bible defines it) is the degree to which that person, church or religious institution is apostate. The church teaches many biblical truths, but also teaches many lies. To the degree that any person or institution teaches against the truth of the Bible is to the degree to which that person or system is apostate or a part of the Babylonian mystery religious system, which YHVH is currently calling his people out of as per Revelation 18:4.
The word Babylon means “confusion or mixture,” and it’s a confusion of truth and lies, good and evil, like the tree by that name. The devil or serpent is in the details. However, when we read the details of Scripture and put the pieces of truth together (“here a little, there a little” and “rightly dividing the word of Elohim”), a very different picture emerges, and it’s not always a pleasant picture either; namely how humans have often twisted and eviscerated the pure light of YHVH’s biblical truth, with the help of the serpent who is slyly hiding camouflaged in the tree of the knowledge of good and evil.
What is the main point I’m trying to make here? Simply this. None of is right before YHVH. (Only the imputed righteousness of Yeshua and the work of the Spirit of Elohim in our lives makes us right before the Kadosh One of Israel.) To the degree that any of us (including our Christian, lost sheep of the house of Israel brethren) aren’t walking according to the light of the truth of both the Living and Written Torah-Word of Elohim is to the degree that we are apostate and under the control of the world, the flesh and the devil.