Jesus taught his disciples to call God, Father, in their prayers (Matthew 6:9–13; Luke 11:1–4). In doing so, he encouraged his followers to consider themselves as sons and daughters of God. When the Spirit brings believers to cry out Abba, Father,
he reminds them of their new status. He makes them conscious of and imparts the assurance of sonship,1 the assurance that the believer truly belongs to God.2
6 And because you are sons, God has sent the Spirit of his Son into our hearts, crying, “Abba! Father!”