But you're talking works here, not salvation. We can do nothing without Christ and the Spirit after being saved. All our good works are to the credit of God.
I need to be careful here because most Protestants don't use these terms as scripture does. Salvation wrought be Christ is eternal, permanent and man cannot contribute a thing to Christ's work. It is why we needed Christ.
However, the purpose of Christ's salvation of the world from death, sin and Satan was to make possible the union of man and God in order that man could freely attain eternal life. This attaining eternal life is a person's individual salvation and it is all about work, working through faith.
But God did not have to save us.
In neither case did He need to save us. However the Gift of love, grace and mercy to man also enabled Christ again to have dominion over this world by defeating Satan. He could have permitted His creation as well as man to be continually dissolved by death but they He would not have been Sovereign over His own creation.
He chose to reckon our faith as righteous, but this was His gift.
but righteousness is not salvation. This does not save a man. It simply puts a person into a correct relationship with Christ in order that he might attain eternal life.
We did not have any role in God making that decision. This was a choice He made alone
You are correct in that God created this world and man in it. But He also set up how man would operate in this world. We either do His will or our own will, but the choice is all ours and every single human being.
He could have let all believers perish with unbelievers and we are all ungodly, but He chose not to. He chose to accept faith as righteousness. We had no say in that matter.
What you fail to understand is that Christ redeemed all sinners, mankind, no one was left out. Rom 5:6-10. Col 1:20. This gift makes it possible for all men to be able to believe and have a relationship with his Creator. Thus you did have say in that you chose to believe. God did not compel you to believe, He cannot compel you to remain faithful. You are completely free to be in union with God or not to be. For that reason there will be a judgment.
We are responsible for our actions and choices. Neither God nor Satan makes you do anything that you do not desire to do.