After Christ had redeemed us, and in Him we had received the position of children, the Father sent the Spirit of His Son into our hearts to cry, Abba, Father (Romans 8:15). The worship in spirit is the worship of the Father in the Spirit of Christ, the Spirit of sonship. This is the reason Jesus uses the name of Father here. We never find one of the Old Testament saints personally appropriate the position of child or call God his Father. The worship of the Father is only possible with those to whom the Spirit of the Son has been given.
