How do Trinitarians reconcile Jesus' words in John 5:31 with the view that GOD the Father / the Son / the Holy Spirit are the same being?

In John 5:31, Jesus said the following: > **If I testify about myself, my testimony is not true.** There is another > who testifies in my favour, and I know that his testimony about me is > true. ‘You have sent to John and he has testified to the truth. Not > that I accept human testimony; but I mention it that you may be > saved. John was a lamp that burned and gave light, and you chose for a > time to enjoy his light. ‘I have testimony weightier than that of > John. For **the works that the Father has given me to finish – the > very works that I am doing – testify that the Father has sent me. And > **the Father** who sent me **has *himself* testified concerning me**. (John > 5:31-37) Jesus spoke for himself as the **Son of God**, but said "if I testify about myself, my testimony is *not* true". It means that his word alone would not suffice for the testimony to be established as proof legally in front of human judges. Jesus refers to John the Baptist as a human witness but adds that "he doesn't accept a human testimony" for "I receive not honour from men" (John 5:41 - KJV). Witnesses acceptable to Jesus' standards of perfection were "the works that the Father has given [Christ] to finish", and in connection with those works, "**the Father** who sent [Christ] **has *himself* testified concerning [Jesus]**. He repeated similar words in **John 8:17, 18** > In your own Law it is written that the testimony of ***two* witnesses** is > true. **I am *one* who testifies for myself**; my ***other* witness** is **the > Father**, who sent me. (John 8:17-18) Jesus says "in your own Law it is written that the testimony of *two* witnesses is true". He clearly follows that Law as well in **John 5:31-37** in regards to the legality of his witness. Who are the ***two* witnesses** Jesus mentions in John 8:17,18? **Himself** and **the Father**! According to the Athanasian Creed , the Trinity is “one God in Trinity, and Trinity in Unity;” and that you can’t “confound the persons nor divide the substance.” Albeit being 3 separate persons, they are **consubstantial** and “**coequal**” for “Such as the Father is, such is the Son, and such is the Holy Spirit” The persons are all almighty, “and yet they are not three almighties, but **one** almighty.... they are not three Gods, but **one** God.” It goes as far as to say that it is “forbidden by the catholic religion to say; There are three Gods or three Lords.” The three persons of the Trinity are inseparable and **ONE** being. The Doctrine of Circuminsession (perichoresis) says: > The subsistences [divine persons] then we say are perfect, that we > may not conceive of the divine nature as compound. For compoundness is > the beginning of separation. And again we speak of the three > subsistences as being in each other , that we may not introduce a > crowd and multitude of Gods. Owing to the three subsistences, there is > no compoundness or confusion: while, owing to their having **the same > essence and dwelling in one another**, and being **the same in will, and > energy, and power, and authority, and movement**, so to speak, we > recognise the indivisibility and the unity of God. For verily there is > one God, and His word and Spirit. According to the theologian studies on the Lutheran Trinity Doctrine, Reiner Jansen said the following: > The"works of the Trinity ***cannot*** be lined up alongside one another in > such a way that they stand as three isolated and **disparate** events. The > work of any given person is always seen in relation to the work of the > other two persons. And so the work of the Father, Son, and Spirit are > not considered in and of themselves, but are seen entirely in the > light of the Trinitarian faith" (Jansen, 84) Dr. Charles P. Arand adds to this: > for there exists an intimate **interdependence**, one might even say a > mutual dependence among their works. James E. Dolezal states: > “The doctrine of divine simplicity teaches that (1) God is **identical** > with his existence and his essence and (2) that each of his attributes > is **ontologically** **identical** with his existence and with every other one > of his attributes.” > > *― James E. Dolezal, God without Parts: Divine > Simplicity and the Metaphysics of God's Absoluteness* If the trinitarian dogma is true, that "the Father, the Word, and the Holy Spirit… are one" (1. John 5:7 - KJV) **"ontologically identical"** in essence and being, then the "witness" they are bearing **about *each other*** is legally unacceptable by the Judaic Law that God himself established! Even if you say that God the Father, God the Son, God the Holy Spirit are *different* persons of the God-Head, it would still be legally unacceptable due to the very nature of God's subsistence according to the Trinity dogma: **The three persons are **one and the same** being: GOD.** Legally speaking you cannot separate the witness from the being giving the witness. If the three persons of the Trinity are **ONE** in essence, nature, power, action, and will, and thus ***cannot*** say, act, and will differently from each other, then we cannot get three separate, distinct or **independent** testimonies from it, but only **one**. For there is no variation in point of view or dependence, that would warrant it to be accepted as a separate **independent** witness. Jesus' own words would apply that "if I testify about myself [my identity], my testimony is not true". It would mean that if any person of the God-Head, testifies about any other person of the God-Head or about the God-Head itself, according to the judicial Law established by God/YHWH himself, this testimony alone would not be acceptable to Jewish judges abiding to that Law.