Romans 4:1-16

Salvation was by grace through faith even in the old testament. "Abraham believed God and it was counted unto him for righteousness."

"It is of faith that it might be by grace."

The grace of God is not that he enables an elect to be sanctified, but that he gives all the revelation through creation and the opportunity to partake of his grace through faith.
I will show grace to others because You have shown me grace.