WHAT IS THIS GIFT OF GOD WHICH BRINGS SALVATION TO MAN?

It is the atonement made by Jesus Christ, by which He took away the sin of the world.

"For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God." (I Peter 3: 18).

"Behold the Lamb of God, which taketh away the sin of the world." (John 1: 29).