What warnings did Paul give to the church?

In Acts 20, Paul provides a sobering warning to the Ephesian elders about the inevitable arrival of 'grievous wolves' that would come to threaten the church. He stresses the importance of vigilance and not sparing the flock from such deceitful influences. These wolves, signifying false teachers, arise both from outside the church and from among its own members. This corresponds to the broader theme in Scripture addressing the need for discernment in doctrine and leadership within the church, highlighting the necessity to 'watch and remember' the teachings of the apostles and to remain anchored in the truth of God’s Word.