Note 2 at Acts 11:23: Barnabas witnessed the grace of God in the lives of these Gentile believers. It can be supposed that he saw and heard evidence of the baptism of the Holy Ghost (as well as the fruit of the Spirit-Gal. 5:22-23) and was thereby convinced that they were true believers, in the same way that the baptism of the Holy Ghost convinced Peter that Cornelius was born again (see note 4 at Acts 11:17, p. 637).

Note 3 at Acts 11:23: The word "purpose" is defined by the New American Heritage Dictionary as, "determination; resolution." It takes effort to cleave (see ref. j at this verse) to the Lord. Without this determination or resolution, our hearts will naturally become hardened towards the Lord (see note 10 at Mk. 6:52, p. 238; Heb. 3:13). People don't intentionally fall away from the Lord. It happens because they neglect their salvation (Heb. 2:3). Rehoboam, the son of Solomon, "did evil, because he prepared not his heart to seek the Lord" (2 Chr. 12:14).