WORD OF WISDOM

CALL - To cry for help, hence to pray (Genesis 4:26). Thus men are said to "call upon the name of the Lord" (Acts 2:21; 7:59; 9:14; Romans 10:12; 1 Corinthians 1:2).
An effectual call is something more than the outward message of the Word of God to men. It is internal, and is the result of the enlightening and sanctifying influence of the Holy Spirit (John 16:14; Acts 26:18; John 6:44), effectually drawing men to Christ, and disposing and enabling them to receive the truth (John 6:45; Acts 16:14; Ephesians 1:17).

SOURCE: Easton's Bible Dictionary