Jesus repeatedly spoke about His 'Father'. He was not talking about Joseph, the husband of his mother, Mary, and the religious leaders knew that. The 'Father' was clearly identified as being God; as in Isaiah 63:16 "… you Lord are our Father, our Redeemer from of old is your name" and in Psalm 89:26 "He will call out to me, 'You are my Father, my God, the Rock my Saviour."