Romans 8:15We have a Spirit-produced awareness of the rich reality that God has made us his children and, therefore, that we can come before him without fear or hesitation as our beloved Father. It includes the confidence that we are truly sons of God. Abba! An informal, Aramaic term for Father that conveys a sense of intimacy. Like the English terms “Daddy” or “Papa,” it connotes tenderness, dependence, and a relationship free of fear or anxiety
John MacArthur Study Bible