Salvation IS a gift but it can be lost thru sin? Soooo...you have to earn it back?
No. Where did you get such a silly idea? If we have lost our salvation through serious sin, we must repent: acknowledge that are actions were sins, have sorrow for them, have the firm purpose to sin no more, and ask Jesus to graciously forgive our sins through his ministers to whom he gave the power to forgive sins:
[Jesus] said to them again, “Peace be with you. As the Father has sent me, so I send you.” And when he had said this, he breathed on them and said to them, “Receive the holy Spirit. Whose sins you forgive are forgiven them, and whose sins you retain are retained.” (John 20:21-23)All of this is through the grace of God; it is not something we earn. Repentance from sin after baptism adds no more to Jesus' salvific action than does our act of faith in him in the first place.
Good question. Oh, no, they will assert! It is ALL because of God's grace, they will claim. BUT...if you can lose something (a gift) by your actions, how can they claim it is a gift or it's grace??? Grace means undeserved, unmerited, unearned, you can't work or DO anything to get a gift by grace. You receive a gift - God says you believe in what Christ has done for you and He imputes the righteousness of Jesus Christ to you, He clothes you in the robes of Christ's righteousness and not your own (because our own righteousnesses are filthy rags). Because we haven't yet died and gone to be with Him in heaven, we are still waiting. So if we can lose our salvation by sinning, then it can't be by grace we are saved. It's either grace OR works - not both. If it's grace, then it can't be by works because then grace wouldn't BE grace and vice versa (see Romans 11:6).