What can we do? Or is it grace?

Romans 9:15-16 “For he saith to Moses, I will have mercy on whom I will have mercy, and I will have compassion on whom I will have compassion. So thenit is not of him that willeth, nor of him that runneth, but of God that sheweth mercy.”

Romans 9:18 “Therefore hath he mercy on whom he willhave mercy, and whom he will he hardeneth.”

Romans 9:30-31 “What shall we say then? That the Gentiles, which followed not after righteousness, have attained to righteousness, even the righteousness which is of faith. But Israel, which followed after the law of righteousness, hath not attained to the law of righteousness.”

Ephesians 2:8-9 “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.”

2 Timothy 1:9 “Who hath saved us, and calledus with an holy calling, not according to our works, but according to his own purpose and grace, which was given us in Christ Jesus before the world began,”

What is God’s purpose for each of us that has little to do with our own works?

And how do we obtain the faith [belief and ultimately trust] that the grace God has already given us is enough?