John wrote his Letter as an encouragement to the members of his community, as they faced difficulties in their new life as Christians. He was an Apostle and a shepherd of his people, God's people. Hence, his encouragement was necessarily a spiritual encouragement and his Letter is very spiritual.

Faith, morality and spirituality are necessarily intertwined, and so a spirituality grounded in good doctrine will lead to a more informed and vigorous moral life. Faith is not in any way a mere opinion: it is a very certain knowledge born of religious love, primarily God's love for us shown in the incarnation of Jesus. Therefore faith will bring us certainty about our relationship with God. So John speaks of this certainty by teaching us "the way we can be sure of our knowledge of Jesus is to keep his commandments." God's commandments are first of all words of God or words of Jesus. As such they are revelations, invitations, promises as well as Commandments. All God's words reveal to us a true way of life and a promise of the grace necessary to live this life to the full in union with Jesus, who came that we might have life and have it to the full (John 10:109).