In today's first reading, John is arguing against some teachers who were misguiding the early Christian community. He is at pains to emphasise that our faith in Jesus as the Son of God is based not only upon the revelation of the Father at the moment when Jesus was baptised in the Jordan (witness of water), but also upon His sacrificial death on the cross which revealed the depths of God's love for the human race (witness of blood). Furthermore, our faith in Jesus is based upon the witness of the Holy Spirit (witness of the Spirit), present in the life and experience of the Christian community, who enables us to profess our faith in Jesus.

As St Paul also stated in his letters, we cannot come to a belief in Jesus without first having received God's Spirit in our hearts who enables us to profess faith in the Lord. Ultimately, John is arguing that God Himself is the One Who gives witness to His Son, enabling us to believe in Him. We are also invited to recognise the ways in which the Holy Spirit continues to witness to the Lord by animating the Christian community to become the presence and power of God in our world today.

In the Gospel, the reputation of Jesus spread because of Him healing the sick. This is also a great witness to Jesus as the Son of God.