Christ will never leave us. That is not the issue. The issue is whether we can freely choose to leave Him. And to the OP has shown support for that, as well there being dozens of other passages, including from Paul, that support that.
Am I the only one who's bovine skubalon detector goes off whenever somebody insists that there are "dozens of passages", but doesn't bother to cite any or tell us what those verses are?
Christ will never leave us. That is not the issue. The issue is whether we can freely choose to leave Him. And to the OP has shown support for that, as well there being dozens of other passages, including from Paul, that support that.
What you're failing to take into account is that salvation was not ours to choose, was not ours to earn, is not ours to keep, and is not ours to lose. Our salvation belongs to God. It was His choosing, His work, and for His glory.
It is God who chose us before the foundations of the world, who called us, who regenerated us, who saved us, who indwells us, who sealed us, and who keeps us.
If God chose us, we cannot unchoose ourselves. If God saved us, we cannot unsave ourselves. If God regenerated us, we cannot unregenerate ourselves. If God indwells us, we cannot unindwell ourselves. If God sealed us, we cannot unseal ourselves. If God keeps us, then we cannot unkeep ourselves.
The second thing you're not taking into account is, if our carnal nature has been crucified with Christ and is dead and we have received a new nature upon regeneration. Where does the Bible ever say that we can give up the new nature we received upon regeneration? And why would a person who had received this new nature want to give it up? Isn't the foremost characteristic of the new nature that it is spiritual and not carnal?
And, for that matter, what replaces the new nature if one can give it up, since the old nature is dead? Do you get a new old nature? And, if so, how?
How does one give up the new nature? Is it like an Islamic divorce, where you just announce, "I divorce you" three times? Is there a document to sign or a ritual to perform?
Think about the consequences of rejecting the Biblical doctrine of eternal security for a moment. If we could really lose (or choose to give up) our salvation, then Hebrews 6:4-6 says that if we ever sin after being saved, we'll be lost forever with no way back, because the Lord would have to be crucified all over again to retrieve us. BTW, it only takes one sin to fall away, right? I mean, one sin before we're saved was enough to condemn us, so one sin after we're saved is enough to condemn us, right? Doesn't this make the New Covenant worse than the Old? Under the Old Covenant, the Israelites were condemned for their actions, but we'd be condemned for our thoughts.
Under the Old Covenant, under the law, the Israelites couldn't murder. We couldn't even be angry. They couldn't commit adultery. We couldn't even have a lustful thought. If you're right, then we lose our salvation by doing less in following the law than the Israelites did!
Is this really the Good News of Jesus Christ? Are these the riches of His Grace, that we have to live in fear of sinning? Are we saved by grace only to be placed under the constraints of an even more severely administered law?
And what of Romans 8:29-30, which says that God predestined those whom He foreknew to be conformed to the image of Christ. If we can lose our salvation and, thus, our conformity to the image of Christ, then does this mean that God's foreknowledge is wrong? That's open theism, which has historically been condemned as heresy by the Church.
How about Jude 24, which says that Christ is able to keep us from falling? If we can lose our salvation, does this mean that Christ is able to keep us from falling, but is merely unwilling? How is that consistent with the Biblical description of Christ?
What do you make of Colosians 3:1-4, which promises that if we have been save, we will appear with Christ in glory? It doesn't say "you might appear with Christ in glory, if you don't lose your salvation". It says "you will appear with Christ in glory". Done deal.
Philipians 1:6 promises us that if Christ has begun a good work in us, that He will finish it. How does He keep that promise if you believe you can lose your salvation?
How do you explain 1 Peter 1:23, which tells us that when we are born again, we are born of incorruptable seed? If we can lose our salvation, then this seed is corruptable and that promise is not true.
Like Colosians 3:1-4, 1 John 3:2 says that we are sons of God now and that when Christ appears, we will be like Him. There is no qualifier. There is no "...if we don't lose our salvation".
Titus 1:2 says that God has promised us eternal life and that He never breaks a promise.
In John 10:27-29, Jesus promises us that He has given us eternal life, that we will never perish, and that we are not only in His hands, but in the Father's hands. How is Jesus' promise in John 10:27-28 consistent with the idea that we can lose our salvation? Is Jesus really incompetent to keep those whom the Father has given Him?
John 5:24 says that if we are saved, we will not come into condemnation but will have eternal life? How can Jesus promise that we will not come into condemnation if He knows we can lose our salvation?
Romans 11:6 tells us that salvation is not by works. If we cannot be saved by works, then how can we lose our salvation by works?
John 14:16-17 tells us that when we are saved, the Holy Spirit indwells us forever. How can the Holy Spirit indwell in us forever if we lose our salvation? Since when does the Holy Spirit dwell in the unsaved?
Ephesians 1:13, 4:30 tells us that we are sealed unto the day of redemption. If we lose our salvation, then how can we still claim to be sealed?
1 Peter 1:4 says that our salvation is "imperishable, undefiled, and unfading". If our salvation is imperishable, how can we lose it? If our salvation is promised by God to be undefiled, how can we defile it?
Salvation is by Living Christ as Lord and Savior
If salvation is by how we live, then that's a works based salvation and a works based salvation cannot save.
The grace of that faithfulness is the only power that enables us to live according to His will.
Out of curiosity, do you agree with this verse:
"For we labor diligently to write, to persuade our children, and also our brethren, to believe in Christ, and to be reconciled to God; for we know that it is by grace that we are saved, after all we can do."
