He answered them, ‘My Father is working until now, and I myself am working.’ For this reason therefore the Jews were seeking all the more to kill him, because he not only was breaking the Sabbath, but also was calling God his own Father, making himself equal with God (John 5:17-18). Although it doesn't mention the Holy Spirit, this verse is usually quoted to support a co-equal trinity. Let us study this verse's context and also look at other passages where Jesus directly states what kind of relationship he has with the Father.

Trinitarians promote the theory that God and Jesus always existed eternally – with no beginning. If the question is asked whether Jesus and God will always exist, then the answer is yes, according to the Scriptures. But if the question is about whether God and Jesus both did not have a beginning, then the answer has to be researched further from the Scriptures. Let us look at some passages on this topic. Also the terms Father and Son themselves help us understand it better.