We have said that the Greek word for apostasy means "to fall away, to revolt, to defect, and to abundant the faith." In these end times or the last of the last days many will DEPART from the faith. We cannot sin away our salvation, but what happens when we walk away from the faith? We are saved by faith and we are kept by faith.
When we say someone walked away from the faith we do not mean they walked away from the church services or other Biblical disciplines. Faith is an issue of the heart. In fact, from the Biblical examples we have, I don't believe that someone who has walked away from the faith realizes that it is or has happened to them.
There are 5 evidences in the Word of God that reveals a person is truly born again:
1. Biblical Evidence: This is a person's testimony of praying to receive Christ.
2. Internal Evidence: This is the witness of the Holy Spirit within the person.
3. External Evidence: This is the fruit of the Holy Spirit manifesting outwardly.
4. Fraternal Evidence: This is the love for the Christian brothers.
5. Paternal Evidence: This is the spanking of the Father if in sin.
These are explained in detail in my book "THE FIVE WITNESSES OF SALVATION" https://www.amazon.com/CHARLES-W-MORRIS/e/B07SR5X3K6?ref_=pe_1724030_132998060
DEPARTED FROM FAITH:
1 Timothy 4:1-3 ESV Now the Spirit expressly says that in later times some will depart from the faith by devoting themselves to deceitful spirits and teachings of demons, (2) through the insincerity of liars whose consciences are seared, (3) who forbid marriage and require abstinence from foods that God created to be received with thanksgiving by those who believe and know the truth.
The Greek says “shall depart” means to remove, revolt, depart, desert, or withdraw self from the faith.
Some would say that these were never saved, or never were in the faith. However, how can one depart from something they never had? How can I fall off a ladder I never climbed up on? The Greek says that in departing they deserted, revolted against, withdrew themselves, and removed themselves form the position of faith. If I am saved by faith, I am kept by faith.