For this cause therefore the Jews sought all the more to kill him, because he not only broke the Sabbath, but also called God his own Father, making himself equal with God.
Jesus was equal with God in His essence. Both the Father and the Son are deity. However Jesus was not equal with the Father in His subsistence. The Son was subordinate to the Father in this respect. This distinction is one that the Jewish leaders struggled with and that Jesus proceeded to clarify partially.