After we have been regenerated and commit a sin, without repenting of it, the only thing that we have lost is our fellowship with God, because God does not fellowship sin. We do not lose our inheritance of eternal life. After regeneration, we have been given the fleshy heart whose conscience can be pricked to feel guilty, and when we repent, we regain our fellowship back with God.
All of those that Christ died for on the cross are saved eternally in a covenant relationship with God, and they consists of only those that his Father gave him to die for. So, Yes, Once saved, Always saved.
You are deceived,
Hebrews10:26 For if we sin wilfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins,
10:27 But a certain fearful looking for of judgment and fiery indignation, which shall devour the adversaries.
James 5:18 And he prayed again, and the heaven gave rain, and the earth brought forth her fruit.
5:19 Brethren, if any of you do err from the truth, and one convert him;
5:20 Let him know, that he which converteth the sinner from the error of his way shall save a soul from death, and shall hide a multitude of sins.
2 peter 2:20 For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning.
2:21 For it had been better for them not to have known the way of righteousness, than, after they have known [it], to turn from the holy commandment delivered unto them.
2:22 But it is happened unto them according to the true proverb, The dog [is] turned to his own vomit again; and the sow that was washed to her wallowing in the mire.
I WANT YOU TO KNOW THAT THE ONLY WAY THEY COULD GET WASHED IS THROUGH THE BLOOD OF YESUAH, THIS tells us that if we fall back out in SIN THAT IT WILL BE WORSE FOR THOSE THAT WAS SAVED, THEN THOSE THAT THAT HAVE NEVER KNOWN THE WAY, THEY WILL HAFT TO SUFFER MORE,