Thanks Chesster,
I found this:
"291. – Then when he says, and then commit apostasy, he shows the difficulty in rising, after one has fallen. Here it should be noted that he does not say, ‘fallen’, but ‘fallen away’, i.e. completely fallen, because if they had merely fallen, it should not be difficult to rise: ‘A just man shall fall seven times, and shall rise again’ (Pr. 24:16).
But if the Apostle had said it is impossible for those who have fallen away to rise again, then it might be said that in this he was signifying how extremely difficult it is to rise, both because of sin and because of pride, as in the devils.
But because he says that those who have once fallen away cannot be renewed unto penance, and there is no sin in this world that man cannot repent of, there must be another explanation.
Hence, it should be noted that a certain Novatian, who was a priest of the church in Rome, made this the occasion of his error. For he declared that no one could rise to penance after baptism.
But this opinion is false, as Athanasius says in a letter to Serapion, **because Paul himself received the incestuous Corinthians, as shown in 2 Cor (chap. 2); and likewise in Gal (4:19), because he says: ‘My little children, of whom I am in labor again, until Christ be formed in you.’ **
Therefore, it must be understood, as Augustine says, that he does not say that it is impossible to repent, but that it is impossible to be renewed again, i.e., baptized: ‘By the laver of regeneration and renovation of the Holy Spirit’ (Tit 3:5).
For a man could never repent in such a way that he could be baptized again. The Apostle says this because according to the Law, the Jews were baptized frequently, as is shown in Mark (chap. 7). Consequently, it was in order to remove that error that the Apostle says this.
- – Then when he says, since they crucify the Son of God on their own account, he gives the reason why baptism cannot be repeated, namely because baptism is a configuration to Christ’s death, as is clear from Romans (6:13); ‘all we who are baptized in Christ, are baptized in his death.’ But this death is not repeated, because ‘Christ rising again from the dead, dies now no more’ (Rom. 6:9).
Therefore, those who are repeatedly baptized crucify Christ again.
Or, another way, it denotes that is is repugnant to Christ’s grace for people to sin frequently and then be baptized again.
Then the emphasis is not on the repitition of baptism, but on the falling away of the sinner, who, as far as in him lies, crucifies Christ again: ‘Christ died once for our sins’ (1 Pt. 3:18).
Therefore, when you sin after baptism, then as far as in you lies, you give occasion for Christ to be crucified again; and in this way hold him up to contempt and stain yourself, washed in His blood: ‘He loved us and washed us fro our sins in his blood’ (Rev. 1:15)."
