Here's a gem from Polycarp's Letter to the Philippians. The translation is that of Michael Holmes.

For everyone "who does not confess that Jesus Christ has come in the flesh is antichrist"; and whoever does not acknowledge the testimony of the cross "is of the devil"; and whoever twists the sayings of the Lord to suit his own sinful desires and claims that there is neither resurrection nor judgment—well, that person is the first-born of Satan. Therefore let us leave behind the worthless speculation of the crowd and their false teachings, and let us return to the word delivered to us from the beginning; let us be self-controlled with respect to prayer and persevere in fasting, earnestly asking the all-seeing God "to lead us not into temptation," because, as the Lord said, "the spirit is indeed willing, but the flesh is weak". (Poly 7.1-2)

What's interesting to me in this section is how Polycarp uses references from First John, First Peter and Matthew to provide basis of his condemnation of those who teach and subscribe to improper doctrine. This is interesting in light of Hill's thesis that Polycarp might be Irenaeus' anonymous presbyter, doing the work of heresiologist and perhaps even providing Irenaeus with the foundation to do the work he later did against heresy.