"See then the kindness and the severity of God: severity toward those who have fallen, but God’s kindness to you, provided you continue in his kindness; otherwise you too will be cut off" (Rom. 11:22)
"I pummel my body and subdue it, lest after preaching to others I myself should be disqualified" (1 Cor. 9:27).
"I am not aware of anything against myself, but I am not thereby justified. It is the Lord who judges me" (1 Cor. 4:4).
"Therefore, my beloved, as you have always obeyed, so now, not only as in my presence but much more in my absence, work out your own salvation with fear and trembling." Philippians 2:12
We can see that Paul warns us that we have to continue in our journey of faith, lest we be cut off. And he even remarks that he struggles and works to subdue his body lest he be disqualified. And he admits that while he's not aware of anything to disqualify himself, he's not the final arbiter. And as he was in prison, he tells us that we need to work out salvation. Showing us that salvation isn't just a one time event for us, but a continuing process.
We can be hopeful, but the heart can be very deceitful (Jer. 17:9), and we must be careful to not be overconfident.
I will have to disagree with your interpretation of the Scriptures. Scripture must be read in context to who, what, where, when and why.
Romans 11:22
Paul is referring to the Gentiles as a group. They could fall out of God's favor, just as the Jews had, as a group. This verse has nothing to do with the losing of salvation. If it had, the bible would be in contradiction of many other verses and God's promise.
1 Corinthians 9:27
in context to the passage Paul is discussing rewards in heaven, not eternal security. The bible is clear that one cannot earn their salvation. Earning your salvation is impossible. If we were able to earn our salvation, Jesus' sacrifice on the cross would have been in vain. Salvation is a free gift.
We are saved for good works, not by good works. Still, the Christian life is a race, a race to accomplish what God put us here for, a race to present ourselves approved unto God, a race to finish in a way so as to hear God say, “Well done, good and faithful servant.” Living for God’s approval requires finishing well.
1 Corinthians 4:4
What Paul is saying here it is insignificant to be judged by other men or himself.
Christians should not be motivated by an overwhelming desire to be popular with men. Our hearts should be set on living our lives acceptably before God. Though Paul's conscious was clear (which does not justify sin), his clear conscious is not the judge. Have to understand that all will be judged, saved and unsaved. We will all have to give an account before God. The difference is one is forgiven and the other is not. Also take note who Paul was addressing here. The Church of Cornith was divided and pretty much a mess.
Philippians 2:12
Let's look at Ephesians 2:8-10, "For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: not of works, lest any man should boast. If we are to earn our salvation, wouldn't these verses contradict one another. If there is a contradiction here then God is not perfect and if God is not perfect, it would be safe to assume He is a liar. If that is the case, we are all doomed.
What is being said is there are two kinds of salvation. There is salvation of the soul and salvation of the life. It is impossible to work out God's salvation, but you are commanded to work out your own. In Colossians 1:16 all things have been created through him and for him. Pay attention to "for him." That should grab your attention. Not only were we created by God, we were created for him. Then jump up to Colissians 1:1-1 Paul, an apostle of Christ Jesus by the will of God, and Timothy our brother. You can see here it is God's "will" for Paul to be an apostle of Jesus. God's salvation is His work, but He has also prepared good works for me that I should be ready to do because that is His will and is for Him. Our eternal salvation is a work done by God. I cannot work out my eternal salvation, but I can work out the salvaging of my life by following God's will.
When you are born again, you are a new creation. You are not an improved version of your former self. But you are brand new. So for a Christian to lose salvation, the new creation would have to be destroyed. A Christian has been purchased with the precious blood of Christ. For a Christian to lose their salvation, God would have to revoke that purchase. A Christian is justified and is declared righteous before God no matter the sins in the past, present, and future. Jesus bore ALL our sins at the cross. For a ChristiN to lose salvation, God would have to go back on His word and undeclare what he had previously declared. A Christian is promised eternal life. For a Christian to lose salvation, eternal life would have to be redefined.
Scripture is clear that God cannot lie so these bible verses that I presented are not in contradiction to the bible verses you presented. So we must conclude the interpretation of these verses from our feeble minds is not accurate.
I like to refer to the thief on the cross who was next to Jesus. He has done nothing to earn salvation, he has not lived the Christian life, he was a thief, yet he was saved from his sins. He was saved because he believed. He believed that Jesus paid his debt on the cross by His blood. He acknowledged his sinnership and repented. He believed that through Jesus he would be forgiven. At that moment a miracle happened and he was born again, a new creation, a new spirit. He never took communion and was never baptized in water, yet he was saved and paradise was promised to him. He may have never prayed, he may have never went to church, he may have never done one good deed, yet he was saved. He was saved because only God can save his soul, grace through faith. God took the complexity of salvation upon Himself at the cross and made salvation simple for us. Now it is our job to do the good works God laid before us for His purpose and glory.