For God says to Moses, “I will have mercy on whomever I have mercy, and I will show compassion to whomever I show compassion.” So then, it does not depend on the person who wants it nor the one who runs, but on God who has mercy. For the Scripture says to Pharaoh, “For this very reason I raised you up, in order to demonstrate My power in you, and that My name might be proclaimed throughout the earth.” So then He has mercy on whom He desires, and He hardens whom He desires. Romans 9:15-18
As believers, we serve a totally sovereign God, who demonstrates His absolute freedom in saving His elect as suits His own purposes. Being the result of His sovereign will alone, the calling of His elect proclaims that salvation does not depend upon man who wills or man who runs but on God who has mercy.
Soli Deo Gloria!