I saw a throne, and on it sat the Father and the Son. I gazed on Jesus' countenance and admired His lovely person. The Father's person I could not behold, for a cloud of glorious light covered Him. I asked Jesus if His Father had a form like Himself. He said He had, but I could not behold it, for said He, "If you should once behold the glory of His person, you would cease to exist." . ... {EW 54.2}

As the crowning act in the great drama of deception, Satan himself will personate Christ. The church has long professed to look to the Saviour's advent as the consummation of her hopes. Now the great deceiver will make it appear that Christ has come. In different parts of the earth, Satan will manifest himself among men as a majestic being of dazzling brightness, resembling the description of the Son of God given by John in the Revelation. Revelation 1:13-15. The glory that surrounds him is unsurpassed by anything that mortal eyes have yet beheld. ...

The Term "Trinity"

Those who reject the traditional formulations of the Trinity doctrine are quick to point out the word does not exist in Scripture. And they are correct. But this provides a very important insight for evaluating those who claim to believe in the Trinity while rejecting traditional formulations.

The term comes from the latin word "trinitas", a word that was created by early Christian theologians in order to explain the Christian understanding of God. Because this is a created word by the very people who held to the "traditional formulations", the word itself is directly and distinctly linked to these formulations. For a person to say that they believe in the Trinity but not in the historical definition of the Trinity is contradictory.

If someone doesn't believe in the doctrine defined by the term "Trinity", rather than hijack the term I believe that they should simply select or create another term to describe their doctrine.

I think the argument is really quite simple, if SDAs believe that the Trinity doctrine is incorrect or incomplete then they should publically acknowledge that they reject the Trinity doctrine and believe in something else instead.

SDA-ism hijacks the term Trinity to use it as a cover for traditional SDA tri-theism. The leadership then tell their ignorant laity that the Denomination does affirm the Christian doctrine of the Trinity, while at the same time teaching the laity a completely different doctrine. The intent is to keep people from realizing that you can't call yourself a regular Protestant Christian and a Seventh-day Adventist at the same time. This deception makes people feel comfortable with their Adventism by allowing them to tell themselves their beliefs aren't all that different from other Protestants after all. That way, they won't get scared and bolt the SDA church.

It also allows them to reach out to Evangelicals, because the "prophetess" said that some day all true Protestant Christians would join the SDAs, so they need to get Evangelicals on board by tricking them into thinking they believe almost all the same stuff.

No, no, no. You're still not getting it (the orthodox, Christian understanding of the Trinity). The phrase "of one substance" does not mean that there are three persons who are all composed of the same type of substance. Rather, it means that God (Father, Son, and Holy Spirit) IS only one substance--one spirit. One single living Being. A spirit Being.

And we do know what God's substance is, we don't have to speculate--Jesus tells us that God is "spirit."

The distinctive characteristic of man’s relation to God is expressed in the declaration of his creation in the image of God. “Let us make man in our image, after our likeness” (Gen 1:26; cf. 5:1-3; 9:6). Elaborate attempts have been made to define what the “image of God” is in which man was created.2 Some contend that it is a physical resemblance between God and man.3 The problem with this view is that it presupposes that God has a corporeal nature similar to that of human beings. This idea is discredited by Christ’s statement that “God is Spirit” (John 4:24), which suggests that He is not bound by space or matter as we are. Moreover, the Biblical terms for the physical aspect of human nature (bashar, sarx—flesh, body) are never applied to God. (Immortality or Resurrection, p. 37)
Also, I believe that the scriptural descriptions of body parts in reference to God are metaphorical, that God was presenting truths about Himself and relating them in human terms. I don't believe that the verses that you quoted above that mention God's "shape" or "form" are talking about a literal, material, physical body. Besides that, the Bible in several places describes God as invisible, but I believe that God appeared in a visible form (not a bodily, material form) at times, such as when He passed by Moses. As you mentioned, angels also have appeared as visible to humans at times and have even looked like humans, but that doesn't mean that they have literal, material bodies.

God saw that a clearer revelation than nature was needed to portray both His personality and His character. He sent His Son into the world to reveal, so far as could be endured by human sight, the nature and the attributes of the invisible God. {CCh 75.6}

Had God desired to be represented as dwelling personally in the things of nature—in the flower, the tree, the spire of grass—would not Christ have spoken of this to His disciples when He was on the earth? But never in the teaching of Christ is God thus spoken of. Christ and the apostles taught clearly the truth of the existence of a personal God. {CCh 75.7}

Christ revealed all of God that sinful human beings could bear without being destroyed. He is the divine Teacher, the Enlightener. Had God thought us in need of revelations other than those made through Christ and in His written word, He would have given them. {CCh 75.8}

One single living Being.

Yes, each member of the Godhead has a physical form. We were made in their image and likeness. I am looking forward to sitting on our Father's lap and staring into His beautiful eyes. "Even little children were attracted to Him. They loved to climb upon His knees and gaze into the pensive face, benignant with love. {SC 11.2}

"How does it play in with Satan's appearing?" I'm not sure there is a connection. It is obvious Jesus came in physical form and that He will return in a similar form. "This same Jesus, which is taken up from you into heaven, shall so come in like manner as ye have seen him go into heaven." (Acts 1:11)

I can't see how "substance," "essence" or "nature" came to be translated as "being." "Person" = "being."

in the trinitarian teaching of the centuries "Person" does not equal "being."
the trinitarian teaching is definitely 3 persons in 1 being.

But this does not reflect the position of Nicea, the Concil where the doctrine of the Trinity began to be formulated. The Greek word is ousia, and at Nicea the controversy was if Christ was of the same ousia as the Father, or of a similar ousia. I can see how this makes sense if the word ousia means "nature," but not if it means "being."
So how can it be translated "three persons in one being"? This translation does not make sense in the context of Nicea.

TRYING TO PUT GOD INTO A FORMULA

IT could not possibly be otherwise, because it was an attempt of the finite to measure, to analyse, and even to dissect, the Infinite. It was an attempt to make the human superior to the Divine. God is infinite. No finite mind can comprehend Him as He actually is. Christ is the Word—the expression of the thought—of God; and none but He knows the depth of the meaning of that Word. "He had a name written, that no man knew but He himself; . . . and His name is called the Word of God." Rev. 19:12, 13. {September 13, 1897 ATJ, BEST 292.5}

Neither the nature, nor the relationship, of the Father and Son can ever be measured by the mind of man. "No man knoweth the Son, but the Father; neither knoweth any man the Father, save the Son, and he to whomsoever the Son will reveal Him." Matt. 11:27. This revelation of the Father by the Son can not be complete in this world. It will require the eternal ages for man to understand "the exceeding riches of His grace in His kindness toward us through Christ Jesus." Eph. 2:7. {September 13, 1897 ATJ, BEST 292.6}

Therefore, no man's conception of God can ever be fixed as the true conception of God. God will still be infinitely beyond the broadest comprehension that the mind of man can measure. The true conception of God can be attained only through "the Spirit of revelation in the knowledge of Him." Eph. 1:17. Therefore the only thing for men to do to find out the Almighty to perfection, is, by true faith in Jesus Christ, to receive the abiding presence of this Spirit of revelation, and then quietly and joyfully wait for the eternal ages to reveal "the depth of the riches both of the wisdom and the knowledge of God." {September 13, 1897 ATJ, BEST 292.7}

An ecclesiastical historian who lived near the time, and was well acquainted with the whole matter, Socrates, has well remarked that the discussion— {September 13, 1897 ATJ, BEST 292.8}

"seemed not unlike a contest in the dark; for neither party appeared to understand distinctly the grounds on which they calumniated one another. . . . In consequence of these misunderstandings, each of them wrote volumes, as if contending against adversaries; and although it was admitted on both sides that the Son of God has a distinct person and existence, and all acknowledged that there is one God in a Trinity of persons, yet, from what cause I am unable to divine, they could not agree among themselves, and therefore were never at peace." {September 13, 1897 ATJ, BEST 292.9}

That which puzzled Socrates need not puzzle us. Although he could not divine why they should not agree when they believed the same thing, we may very readily do so, with no fear of mistake. The difficulty was that each disputant required that all the others should not only believe what he believed, but they should believe this precisely as he believed it, whereas just how he believed it, he himself could not define. And that which made them so determined in this respect was that the strife was not merely for a doctrinal statement, but for supremacy and for political power. {September 13, 1897 ATJ, BEST 292.10}

i posted this topic elsewhere and a possible pantheist has hijacked the thread stressing how the Spirit is "in" everything. could you refute him?

As a witness for Christ, John entered into no controversy, no wearisome contention. He declared what he knew, what he had seen and heard. He had been intimately associated with Christ, had listened to His teachings, had witnessed His mighty miracles. Few could see the beauties of Christ's character as John saw them. For him the darkness had passed away; on him the true light was shining. His testimony in regard to the Saviour's life and death was clear and forcible. Out of the abundance of a heart overflowing with love for the Saviour he spoke; and no power could stay his words. {AA 555.2}

"That which was from the beginning," he declared, "which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of the Word of life; . . . that which we have seen and heard declare we unto you, that ye also may have fellowship with us: and truly our fellowship is with the Father, and with His Son Jesus Christ." {AA 555.3}

He could testify: "That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of the Word of life; (for the Life was manifested, and we have seen it, and bear witness, and show unto you that eternal life, which was with the Father, and was manifested unto us;) that which we have seen and heard declare we unto you, that ye also may have fellowship with us: and truly our fellowship is with the Father, and with his Son Jesus Christ" (1 John 1:1-3). {AG 252.3}

So everyone may be able, through his own experience, to "set his seal to this, that God is true" (John 3:33, A.R.V.). He can bear witness to that which he himself has seen and heard and felt of the power of Christ. He can testify: "I needed help, and I found it in Jesus. Every want was supplied, the hunger of my soul was satisfied; the Bible is to me the revelation of Christ. I believe in Jesus because He is to me a divine Saviour. I believe the Bible because I have found it to be the voice of God to my soul." {AG 252.4}

How shall we know for ourselves God's goodness and His love? The psalmist tells us--not, hear and know, read and know, or believe and know; but--"Taste and see that the Lord is good" (Ps. 34:8). Instead of relying upon the word of another, taste for yourself. Experience is knowledge derived from experiment. Experimental religion is what is needed now. "Taste and see that the Lord is good." {AG 252.5}