Contrast and Contradiction

Today's Epistle includes a promise of salvation - if we call on the name of the Lord, we will be saved.
This seems to contradict Matthew 7:21, "Not everyone who says to Me, 'Lord, Lord,' will enter the kingdom of heaven".
How can we reconcile these seemingly contrary passages?
I think that we need to understand that we can call on the name of the Lord for salvation, but that he then also expects from us action and not just words. Jesus did not just preach, he acted, and ultimately "By His stripes we are healed" (Isaiah 53:5, 1 Peter 2:24)
I have not seen The Passion of the Christ yet, but I am told that the scourging is rather graphic. Well is should be. In our sanitized world where we know that the violence prtrayed on TV and in movies is just fantasy, it is chilling to realoze just what Jesus the Christ suffered for us.
By those stripes we are healed. Thanks be to God.