This is My blood of the new covenant, which is shed for many for the remission of sins. - Matthew 26:28, NKJV
God knew that after our salvation experience, as we sought to live a new life, we would sin again. And because of the continuing struggle with sin and failure in our lives, we would be tempted to doubt our salvation. So God gave us a sign of the new covenant. Jesus said it was the sign of His broken body and His poured-out blood. It was the sign of the cross.
Have you become so overwhelmed with your own weakness and failure and sin and inability to live a life that is pleasing to God that you have begun to doubt your salvation? Then look up! Take a good, long look at the cross and remember that God remembers. He loves you, He has forgiven you, He is eternally committed to you, and you are saved! Forever! Praise God! His covenant is unconditional!
From God's Story