Ante-Nicene Fathers Volume 5
Cyprian: Epistles LII-LIII
Returning again to the question of the lapsed in Epistle LII, Cyprian discusses the case of three believers who had given in under torture, but have been repenting for the past three years. Is it now acceptable to receive them back into communion? Cyprian believes that because these individuals had only given in under extreme torture and had held on so faithfully for so long prior to that, three years of repentance should be enough. Now, that should not mean an easy or cheap grace for others--just those who are in unique circumstances (the sick, the dying, and those who held up under most persecution but gave in when face with difficulties they were not truly equipped for).
And yet, Cyprian says that he will take this discussion to a gathering of elders and come with the opinion of the group, which appears to be what is going on in Epistle LIII. Since it appears that another persecution is on the way, and since we as a church are to be merciful when we can, we should bring those who have been consistently repentant back into the fold so that we might be united when the persecution finally comes. We need the church to be at its best, which means gathered together around the Lord's Table in fellowship and full communion: "how do we make them fit for the cup of martyrdom, if we do not first admit them to drink, in the Church, the cup of the Lord by the right of communion?"
This is not to say that those who have returned to their sinful lives, or embraced heresy, should be readmitted. Only the truly penitent.
Some argue that this isn't really necessary, since being martyred will be enough to bring the lapsed back into the church. Yet, this downplays too much the role of the church in the life of a believer. "he cannot be fitted for martyrdom who is not armed for the contest by the Church; and his spirit is deficient which the Eucharist received does not raise and stimulate."
Now, it's true that God will still receive His own,but what will God say to the church on that Last Day if we have refused to allow the repentant sinner to return? It is our responsibility to declare forgiveness and to be unified in the face of the world's assault, and we must not be found lax in that duty.
Again, we see that Cyprian has perhaps too high a view of the church's role in salvation, but also again that may be a needed corrective to today's individualistic Christianity that would ignore the church all together.