The Divinity concept of divine being has developed over time into a rather heretical concept, through various theological battles over the centuries. Trinitarianism and Oneness are each guilty of some degree of heresy. The Father and Son are individuals and independent. In this sense each is one individual. Jesus said that he himself testifies but the Father is the second witness. For there to be two witnesses, their corroboration or otherwise must be meaningful, which means they must be independent. That is to fulfil the law. So they cannot be both one being. They must be two, independent beings. Not just two persons. Two beings. A shared essence like Trinitarians preach would undermine their independence. Jesus saw no such undermining. He knew that the Father’s testimony is independent to his own. He knew they are two. Two because the law needs two testimonies, independent testimonies.
The Father is one. The Son is one. How then together are they one? How are the Father and the Son one? “May they be one, as We are one,” Jesus prayed. How are the disciples one? In mind, love, spirit, and purpose. (From Philippians 2:2) Similarly Philippians 1:27 “I will know that you stand firm in the one Spirit, striving together as one for the faith of the gospel.” The spirit of how people live and the gospel faith for which they strive, is their unity. “… as We are one”. This means Jesus and the Father are one in this way. Furthermore, Jesus is one with his disciples, and they with each other.
Another battle involving a heretical outcome has been the East/West disagreement about co-equality. Jesus only receives his divinity from the Father. He will subject himself forever to the Father eventually. He will then forever share the Father’s throne, but this is because the Father will share it with him. Yet the further heresy developed. If you live in the West, with Catholicism, Protestantism, you are labelled a heretic if you agree with the East that the Father is greater than the Son, and disagree that they are co-equal in the Trinity. If you live in the East, with Eastern or Oriental Orthodoxy, and you believe this, you would not be labelled a heretic. This very situation is heretical. You should not have to belong to East tradition roots or West tradition roots to avoid charges of being heretical in what you believe. You should not have to switch your allegiance. This concept of having two camps is the very core of worldly heresy.