Acts 2:21 'AND IT SHALL BE THAT EVERYONE WHO CALLS ON THE NAME OF THE LORD WILL BE SAVED.'
For whosoever shall call upon the name of the Lord shall be saved.
For whoso ever shall call upon the name of the Lord shall be saved. See Joe 2:32. To call upon the name of the Lord implies, (1) That the true God (Jehovah, in the Hebrew quotation) shall be approached in worship, and (2) that there shall be something more than saying, Lord, Lord, etc. (Mt 7:21,22). The language, wherever used, implies coming to the Lord and calling on him in his appointed way. Compare Ac 22:16 2:21 Ge 12:8. This promise of Joel, since it says whosoever, is not limited to the Jewish race.
God's appointed way of being saved:
Romans 10:9-10 (King James Version)
9That if thou shalt confess with thy mouth the Lord Jesus (JESUS AS YOUR LORD) , and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.
10For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.
The spirit of the Lord = freedom