The Bible’s answer is NO, NEVER, IMPOSSIBLE!
The only possible thing is to reject it and that is completely up to you. God gave us FREE WILL.
And NO, one does NOT "spiritually" reject SALVATION if you "sin"-- that's religion's scare tactic for "keeping people in line".
God doesn't use fear as a tool to get what He wants from us.
God doesn't need or want anything from us.
God loves- simply that. Religion is guilty for twisting that amazing Truth.
1 John 4:10
This is real love—not that we loved God, but that he loved us and sent his Son as a sacrifice to take away our sins.
1 Corinthians 1:30-31
30 Because of God you are in [united with; in relationship with] Christ Jesus, who has become for us wisdom from God. In Christ we are put right with God, and have been made holy, and have been set free from sin […and became for us righteousness, holiness, and redemption]. 31 So, as the Scripture says, “If people want to brag [boast], they should brag [boast] only about the Lord.
John 14:6
6 Jesus answered, “I am the way, and the truth, and the life [or the one true way to have life]. The only way to the Father is through me [No one comes to the Father except through me].
Romans 8:38-39
38 Yes, I am sure [convinced] that neither death, nor life, nor angels, nor ruling spirits [or heavenly rulers; or demons; Rulers; Principalities], nothing now [in the present], nothing in the future, no powers [or spiritual powers/authorities], 39 nothing above us [or no powers in the sky], nothing below us [or nor powers in the depths], nor anything else in the whole world [any created thing] will ever be able to separate us from the love of God that is in Christ Jesus our Lord.
Galatians 2:20
My old self has been crucified with Christ.It is no longer I who live, but Christ lives in me. So I live in this earthly body by trusting in the Son of God, who loved me and gave himself for me.
1 John 4:18
18 Such love has no fear, because perfect love expels all fear. If we are afraid, it is for fear of punishment, and this shows that we have not fully experienced his perfect love.
Truth... He sets you free.
The Cross of Christ Jesus puts the Bible in perspective. It is the "Rosetta Stone" for God's Word language. Without it, it's just about religion, guess games, traditions, church service.