I totally agree with you that salvation is a gift and there is nothing anyone can do to earn it. Is it possible for someone to accept the gift and years later change their mind and say they do not want it? I accepted Christ in my early 20’s. (I’m now in my early 60’s.) The only reason I can remember for doing so was because I was afraid of going to hell. There are so many things I do in accordance with God’s teaching that are either out of habit or because I feel I should. At times I believe the best I can hope for is a lesser degree of hell.
A number of verses in the New Testament give testimony to the fact that our salvation is a non-returnable gift. Once we are saved they say that our security is guaranteed by God and no one, including ourselves, can reverse that. Here are a few examples. John 10:28-29 says that both the Father and the Son hold us on the palm of their hands, and that no one can snatch us away. It doesn’t say no one but us, it says no one. Romans 8:38-39 says that nothing in all of creation can separate us from the Love of God that’s in Christ Jesus. Nothing in all of creation includes us.
In 2 Cor. 1:21-22 Paul said that God has assumed responsibility for us. He put His mark of ownership on us and His spirit in us to guarantee our future with Him. He has the right to mark us because He purchased us, and we are no longer our own (1 Cor. 6:19-20). The price He paid was the blood of Jesus (1 Peter 1:18-19). We agreed to this, so we belong to Him now and no longer have the right to walk away.
Jesus often used the analogy of the sheep and the shepherd in referring to His relationship with us. A basic tenet of that relationship is that sheep are prone to wandering off and when they do it’s their shepherd’s job to bring them back. Jesus promised never to lose even one of those the Father gives Him (John 6: 37-40). On that day 40 years ago, if you sincerely asked the Lord into your heart, then He’s still there and will never leave you or forsake you. If you’ve wandered off He’s searching for you and will bring you back.
Make it easier on both of you. Start looking for Him again. You’ll find Him in the pages of your Bible. Don’t worry about doing what Christians are supposed to do. Go back to being what Christians are supposed to be, and that’s the object of the Lord’s affection. Open your arms to Him and He’ll embrace you. It’s a promise He’s made and He’s waiting to keep it.
And by the way, there’s no such thing as a lesser degree of Hell.