1st Timothy 4:1, Some Shall Depart From The Faith

1st Timothy 4:1-3, “Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils; Speaking lies in hypocrisy; having their conscience seared with a hot iron; Forbidding to marry, and commanding to abstain from meats, which God hath created to be received with thanksgiving of them which believe and know the truth.”

My humble interpretation of "depart" in 1st Timothy 4:1 is that they were never saved at all. Everybody examines the Christian faith first from a distance, to see if it interests them. That is what the Bible means in Hebrews...

Hebrews 6:4-6, "For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost, And have tasted the good word of God, and the powers of the world to come, If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame."

They merely "tasted" of the heavenly gift. They were enlightened to hear THE TRUTH, but they didn't want it, so they rejected it, which effectively is like crucifying Jesus afresh. Many Bible students get this passage wrong, assuming that it teaches you can lose God's gift of eternal life; but that's not what it means at all. This passage is about lost sinners who have heard the Gospel truth, but didn't believe and were not saved.