Grace is an act of God which has confounded theologians for centuries. Adherents to Christianity find it unfathomable, and it is likely it will never be fully understood until all who are to understand it arrive in their Heavenly dwellings at the end of time itself.

In the broad sense of the word, grace is what God shows by choosing to render salvation instead of wrath. It is God's highest act of love that He has yet to wipe our filthy souls clean off the planet, blotting our existence out of the universe entirely. Instead, He has chosen to make a way for His people to find forgiveness and eternal life.

Put quite simply, grace is when God gives sinful humans that which they do not deserve and cannot earn.

As a subset of grace, you may also find that Christians speak of common grace, special grace, and cheap grace.