1/51.2 The effects of baptism: cleansing from original sin, new life, divine filiation etc. Entry into the Body of the Church.
Almighty ever-living God, who when Christ had been baptized in the River Jordan and as the Holy Spirit descended upon him, solemnly declared him your beloved Son, grant that your children by adoption, reborn of water and the Holy Spirit, may always be well pleasing to you.
Baptism initiates us into the Christian life. It is a true birth into supernatural life. It is the new life preached by the Apostles and spoken of by Jesus to Nicodemus: Truly I say to you that he who is not born again from on high cannot enter into the Kingdom of Heaven: what is born of the flesh is flesh but what is born of the Spirit is spirit.
The result of this new life is a true divinisation of man that gives him the power to bring forth supernatural fruit.
Often the dignity of the baptized person is veiled, unfortunately, by the ordinary circumstances of his life so, like the saints, we must strive hard to live in accordance with that dignity at all costs.
Our highest dignity, that of being children of God, conferred on us by baptism, is the consequence of our re birth. If human birth gives as its result ‘fatherhood’ and ‘sonship’, in a similar way those engendered by God are really his children. See what Love of God the Father has for us that He has called us children of God! We really are! Beloved, now we are children of God and it is not yet shown what we shall be.
The miracle of a new birth is achieved at the moment of Baptism by the outpouring of the Holy Spirit. The baptismal water is blessed on Easter night and in the prayers we ask: Just as the Spirit came upon Mary and produced in her the birth of Christ, so may it descend on the Church and produce in her maternal womb (the baptismal rite) the rebirth of the children of God.
The profound reality corresponding to this graphic expression is that the newly baptized person is born again to a new life, the life of God and thus is His ‘son’: And so we are sons, and heirs too, heirs of God and co heirs with Christ.
Let us give thanks to our Father God for bestowing such gifts, gifts beyond all measure, upon us, upon each one of us. What great joy it is to think often about those realities! ‘Father’, said that big fellow, a good student at the university (I wonder what has become of him), ‘I was thinking of what you said to me – that I am a son of God! – and I found myself walking along the street, head up, chin out, and a proud feeling inside ... a son of God!’ With sure conscience I advised him to encourage that ‘pride’.
 Collect of the Mass
 John 3:3 6
 cf 1 John 3:1 9
 cf Rom 8:14 17
 St J. Escrivá, The Way, 274