Another area of passages some people use to show that one can lose salvation are those that actually speak of false teachers who were never saved to begin with.
Some people use Matthew 7:15 to show that a person can lose his salvation if that person disguises himself in sheep’s clothing. But Yeshua was not dealing with people who were believers who became false teachers; rather, he was dealing with people who were never saved to begin with. They never were “sheep,” but were always “wolves” pretending to be sheep.
Acts 20:29‑30 is also a message dealing with false teachers, either false teachers who may enter in from outside or false teachers who may arise from the inside. However, in neither case were these people saved to begin with. Both are distinguished from the disciples, who are believers.
Romans 16:17‑18 speaks of false teachers who corrupt the church, but it does not say that these false teachers are people who were saved and then lost their salvation.
2 Corinthians 11:13‑15 is a passage that speaks of false teachers and not people who lost their salvation. Verse 13 states that these are false apostles, and in verse 15, they are called Satan’s ministers, not the Messiah’s ministers. Furthermore, it never states that they were apostles of Christ, only that they fashioned themselves to sound like and seem like apostles of Christ. Verse 15 does not state that they “used to be ministers of righteousness,” but that they tried to fashion themselves as ministers of righteousness.
1 Timothy 4:1‑2 deals with the issue of false teachers who were not saved to begin with. This is the area of apostasy. The basic meaning of apostasy is “to fall away from the faith that one professed to have, but never really had.” It has to do with people who made a show of faith, claiming to be believers but then, little by little, gave in to seducing, demonic spirits and teaching of false doctrines.
2 Peter 2:1‑22, particularly verses 19‑22, deals with people who are false teachers and who were never saved to begin with. Verse 1 clearly talks of false teachers coming into the body with destructive heresies, denying even the Master that bought them. Furthermore, Peter said that these were bondservants of corruption (v. 19); they were never the Messiah’s bondservants, who later lost their salvation. These are people who knew the way of righteousness (v. 21); they had a clear knowledge of the truth and were not ignorant of the gospel. But, having rejected the gospel, they then went on a teaching campaign to deny the truths concerning Jesus the Messiah.
1 John 2:19 actually speaks of people who were part of the local body as far as membership was concerned, but were themselves never really saved. Because, as John points out, if they were really saved, they would have continued with us. He did not say, “They used to really be one of us, but lost their salvation and then went out from us.”
Jude 3‑19 speaks of the same group of people: people who knew what the truth was, knew the content of the gospel, but rejected it and then began actively teaching against the doctrine of the Messiah.
 This post is a modified version of Dr. Arnold Fruchtenbaum’s original Messianic Bible Study. The full version may be obtained here.