2 If, therefore, any one wishes to show piety towards God, let him worship the Son, since otherwise the Father accepts not his service. The Father spoke with a loud voice from heaven, saying, This is My beloved Son, in whom I am well pleased. The Father was well pleased; unless thou also be well pleased in Him, you have not life. Be not thou carried away with the Jews when they craftily say, There is one God alone; but with the knowledge that God is One, know that there is also an Only-begotten Son of God. I am not the first to say this, but the Psalmist in the person of the Son says, The Lord said unto Me, You are My Son. Heed not therefore what the Jews say, but what the Prophets say. Do you wonder that they who stoned and slew the Prophets, set at nought the Prophet.' words?
Source: Catechetical Lectures (New Advent)