To fall from grace means you must once have been there. So this must refer to a believer. In that case I will first offer this verse>>30 And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption.
Eph 4:30 (KJV)<<

Now the question will be when is the day of redemption? if a believer is sealed not until he falls from grace how is it that a 'sinner' fallen from grace would be sealed of the Holy Spirit?

Is there a teaching on saving those who have been llost after being saved once?