Like the church in Pergamum, we need to heed the warnings of Christ which will lead us to repentance.
Pergamum was a city that Jesus refers to as being "where Satan's throne is." Powerful forces were at work with the aim of introducing compromise, thus making the church impotent. While many had remained faithful, others had been stained by sexual immorality (among other things), which is the cause for Christ's warning to this church. The good news is that the mistakes and poor choices we make do not need to be the end of the story. The church at Pergamum was invited to repent with a view looking forward to a great reward. That same warning—along with the invitation to repent—is for us today as well.