Note 2 at Ac 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, Ga 5:22-23), and he 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 Ac 11:17).

Note 3 at Ac 11:23: One definition of the word "purpose," according to the American Heritage Dictionary, is "determination; resolution." It takes effort to cleave to the Lord. Without this determination or resolution, our hearts will naturally become hardened toward the Lord (Heb 3:13, see note 10 at Mr 6:52). 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" (2Ch 12:14).