It means believing Jesus died in our place, to bring us back to God, the only One who can satisfy our souls. Now and always.
By believing that Jesus died to take our punishment for our sins, we know that God will be our God forever. THIS IS AMAZING NEWS!!!
For Christ also died for sins once for all, the just for the unjust, so that He might bring us to God (1Peter 3:18)
And in God’s presence in fullness of joy! (Psalm 16:11).