‘When God “chooses” a person for His purposes, He does so according to the person’s heart! The person must have a loyal heart full of trust and faith. God must have a person who loves Him “with all [the] heart, with all [the] soul, and with all [the] strength” (Deut. 6:5; Matt. 22:37). Anything less than this is unacceptable to God for the carrying out of His purposes. Unless the person had such a heart, God would find the person arguing with God, rejecting God, disobeying God, and ultimately straying from God. The eternal purposes of God could not be accomplished in such a person’s life. Only a heart that is thoroughly loyal to Him is acceptable to God.’
source: Henry T. Blackaby, Created to be God’s Friend, p. 16.