One can't teach about Bible prophecy and ignore the book of Revelation. In chapter 2, Jesus rebuked the churches for various errors being practiced or taught in the Christian churches.
The seven churches of Asia had the same problems that plague present-day churches. The churches today fall under the same descriptions as the seven churches then. The only difference is, those seven churches are now spread out world-wide. That's why the warnings and rebukes given then, are relevant today.
Jesus said to the Church of Ephesus:
I know your deeds, your hard work and your perseverance. I know that you cannot tolerate wicked people, that you have tested those who claim to be apostles but are not, and have found them false. 3 You have persevered and have endured hardships for my name, and have not grown weary.
4 Yet I hold this against you: You have forsaken the love you had at first. 5 Consider how far you have fallen! Repent and do the things you did at first. If you do not repent, I will come to you and remove your lampstand from its place. 6 But you have this in your favor: You hate the practices of the Nicolaitans, which I also hate.
7 Whoever has ears, let them hear what the Spirit says to the churches. To the one who is victorious, I will give the right to eat from the tree of life, which is in the paradise of God.
This church worked hard and it would seem, they had all kinds of things coming against them, but they stuck to their guns because of Jesus.
The problem was they had quit loving each other. When that happens you have strife, backbiting and all kinds of trouble move into a church. Sounds like some of today's churches. Their theology is solid. They teach the "full gospel". But when a church stops loving each other, they then stop reaching out and loving others.
They didn't just automatically believe every one claiming to be an apostle. They tried them and found them to be liars. They protected their church from being deceived.
They hated evil. They hated the practices of the Nicolaitans, which Jesus said he also hated.
It seems the Nicolaitans were heretics who tried to throw stumbling blocks in front of Christians by causing them to also indulge in idol worship, eating meat that was being sacrificed to idols and generally living an indulgent lifestyle. The leader had complete control over the lives of his followers.
The church at Ephesus stood strong against that teaching.
However….yes, there's a however….they had quit loving each other and Jesus told them he would remove their candlestick. Translation: Either repent and start loving each other again, or I will shut you down.
How many times have we seen that happen in today's churches? Too often for sure. A church can be be sound in it's theology but they need to remember this:
Corinthians 13:13 And now these three remain: faith, hope and love. But the greatest of these is love.