Romans 8:15 For you have not received a spirit of slavery bringing you into fear again, but you have received a spirit of sonship in which we cry, Abba, Father! Galatians 4:6 And because you are sons, God has sent forth the Spirit of His Son into our hearts, crying, Abba, Father!
It is in the New Testament that the Lord reveals God as the Father who regenerates many sons. He is the source of life; hence, He is the Father. It is His intention to bring forth innumerable sons by regenerating them with His life.
God is the Father because He begets many people with His life, making them His children and His sons. We call Him Father because we were born of Him and have His life. How sweet it is to call God our Father!
“Abba, Father.” Throughout the world, little children use a double title, such as Papa, or Mama, when addressing their parents. To say Pa or Ma is not very intimate. But Papa or Mama is intimate.
Among every race the children call their fathers Papa, Baba, or something similar. If I were not born of my father, yet I had to call him Papa, it would be very awkward. It would even be awkward to address your father-in-law in this way.
It would not be so sweet. God is not your father-in-law; He is your Father, your Father in “life.” Because God is our Father in life, it is so sweet to call upon Him, saying, “Abba, Father.” When you sense this sweetness, you know that you are His child and that He truly is your Father in life.