If the church wasn't at risk from false teachers, Jude wouldn't have needed to write this letter, and neither would have Jesus or the other Apostles needed to warn us about apostates. The threat is real, and there are among us even when we think they are not. The 17th century Puritan John Flavel said this, -By entertaining of strange persons, men sometimes entertain angels unawares- but by entertaining of strange doctrines, many have entertained devils unawares.- There comes a point in every believer's life when we need to acknowledge where we have been influenced by false teaching, and the only way out is to ask God to make Christ so gloriously beautiful to us that we are no longer under the spell of these false teachers. The influence of apostates is powerful, and only the awakening grace of the Holy Spirit can move us from error to truth, and the only path to this awakening grace is through the cross of Christ. So friends trust in him today.