Salvation is a Gift:
For it is by free grace (God’s unmerited favor) that you are saved ([a]delivered from judgment and made partakers of Christ’s salvation) through [your] faith. And this [salvation] is not of yourselves [of your own doing, it came not through your own striving], but it is the gift of God; Not because of works [not the fulfillment of the Law’s demands], lest any man should boast. [It is not the result of what anyone can possibly do, so no one can pride himself in it or take glory to himself.]
EPHESIANS 2:8-9 AMPLIFIED BIBLE
God will never take back a gift from you.
For God’s gifts and His call are irrevocable. [He never withdraws them when once they are given, and He does not change His mind about those to whom He gives His grace or to whom He sends His call.] ROMANS 11:29 Amplified Bible (AMP)
God will never take it back from you. You received it by faith and you keep it by faith.
Even the faith you have is a GIFT from God.
And even trusting is not of yourselves; it too is a gift from God. Eph 2:9
So salvation is a gift you receive from trust. The trust you trust with is a gift. God never takes back gifts. Your salvation is based on Gods gifts and not your ability to keep the law or your good works but it is based on the work of Christ.
Do you see the closed loop here on your salvation. This gives security to the believer and gives you a nice helmet to wear.
Gods yes means yes.
Let your yes mean yes, and your no mean no. Anything more than this comes from the evil one.