If it's not about our effort, then where does salvation come from? Paul points to one glorious source.
The verse pivots sharply at the end: 'but on God, who has mercy.' This is the heart of the matter. The ultimate reason anyone is saved is not because they are inherently more willing or run faster than others, but because God, in His sovereign grace, chooses to extend mercy.
This mercy isn't earned or deserved. It's a free, unmerited gift. The commentators point out that the Old Testament texts Paul draws upon ('I will have mercy on whom I have mercy') highlight God's freedom to bestow His favor. This doesn't mean God is arbitrary; His mercy is perfectly just and aligns with His holy character, but the and the are entirely His.