Barnabas said, “We ought therefore, brethren, carefully to inquire concerning our salvation. Otherwise, the wicked one, having made his entrance by deceit, may hurl us forth from our life.” (c. 70-130, Vol. 1, p. 138)
Barnabas said, “The whole past time of your faith will profit you nothing, unless now in this wicked time we also withstand coming sources of danger….Take heed, lest resting at our ease, as those who are called, we fall asleep in our sins. For then, the wicked prince, acquiring power over us, will thrust us away from the kingdom of the Lord….And you should pay attention to this all the more, my brothers, when you reflect on and see that even after such great signs and wonders had been performed in Israel, they were still abandoned. Let us beware lest we be found to be, as it is written, the ‘many who are called,’ but not the ‘few who are chosen.’” (c. 70-130, Vol. 1, p. 139)
Hermas said, “If you do not guard yourself against [anger], you and your house will lose all hope of salvation.” (c. 150, Vol. 2, p. 23)
Justin Martyr said, “I hold further, that those of you who have confessed and know this man to be Christ, yet who have gone back for some reason to the legal dispensation [i.e., the Mosaic Law], and have denied that this man is Christ, and have not repented before death – you will by no means be saved.” (c. 160, Vol. 1, p. 218)
Irenaeus said, “We should not, therefore, as the presbyter remarks, be puffed up, nor be severe upon those of olden times. Rather, we should fear ourselves, least perchance, after [we have come to] the knowledge of Christ, if we do things displeasing to God, we obtain no further forgiveness of sin, but are shut out from His kingdom. And for that reason, Paul said, ‘For if [God] spare not the natural branches, [take heed] lest He also not spare you.’” (c. 180, Vol. 1, p. 499)
Irenaeus said, “It was not to those who are on the outside that he said these things, but to us – lest we should be cast forth from the kingdom of God, by doing any such thing.” (c. 180, Vol. 1, p. 500)
Irenaeus said, “Those who do not obey Him, being disinherited by Him, have ceased to be His sons.” (c. 180, Vol. 1, p. 525)
Clement of Alexandra said, “God gives forgiveness of past sins. However, as to future sins, each one procures this for himself. He does this by repenting, by condemning the past deeds, and by begging the Father to blot them out. For only the Father is the one who is able to undo what is done….So even in the case of one who has done the greatest good deeds in this life, but at the end has run headlong into wickedness, all his former pains are profitless to him. For at the climax of the drama, he has given up his part.” (c. 195, Vol. 2, p. 602)
Tertullian said, “Some think that God is under a necessity of bestowing even on the unworthy what He has promised [to give]. So they turn His liberality into His slavery….For do not many afterwards fall out of [grace]? Is not this gift taken away from many? These, no doubt, are they who…after approaching to the faith of repentance, build on the sands a house doomed to ruin.” (c. 203, Vol. 3, p. 661)
Tertullian said, “God had foreseen…that faith – even after baptism – would be endangered. He saw that most persons – after obtaining salvation – would be lost again, by soiling the wedding dress, by failing to provide oil for their torches.” (c. 213, Vol. 3, p. 639)
Origen said, “A man may posses and acquired righteousness, from which it is possible for him to fall away.” (c. 225, Vol. 4, p. 266)
Origen said, “Certain ones of those [heretics] who hold different opinions misuse these passages. They essentially destroy free will by introducing ruined natures incapable of salvation and by introducing others as being saved in such a way that they cannot be lost.” (c. 225, Vol. 4, p. 308)
Commodianus said, “Being a believing man, if you seek to live as the Gentiles do, the joys of the world remove you from the grace of Christ.” (c. 240, Vol. 4, p. 214)
Cyprian said, “I ask…that you will grieve with me at the [spiritual] death of my sister. For in this time of devastation, she has fallen from Christ.” (c. 250, Vol. 5, p. 298)
Cyprian said, “There is need of continual prayer and supplication so that we do not fall away from the heavenly kingdom, as the Jews fell away, to whom this promise had first been given.” (c. 250, Vol. 5, p. 451)
Cyprian said, “In the Gospel according to Matthew: ‘Every tree that does not bring forth good fruit will be cut down and cast into the fire’….Even a baptized person loses the grace he has attained, unless he remains innocent. In the Gospel according to John: ‘Look, you are made whole. Sin no more, lest a worse thing happen to you’. Also, in the first Epistle of Paul to the Corinthians: ‘Do you not know that you are the temple of God, and the Spirit of God abides in you? If anyone violates the temple of God, God will destroy him’. Of this same thing in the Chronicles: ‘God is with you, while you are with Him. If you forsake Him, He will forsake you’.” (c. 250, Vol. 5, p. 542)
] that our faith, if we are born anew is protected by the power of God, and thus we can never lose it. So it may be that the people who profess Christ, and then later deny Christ were never born again. Otherwise, in their heart of hearts, they would still love Jesus, or so it seems to me.