Father, Son, and Holy Spirit. The three parts of the Godhead. It's not "non-Biblical". It's a basic doctrine of Christianity.
Yes, and Modalism is not.
John 14:25-26, “I [Jesus] have spoken these things while staying with you. But the Advocate, the Holy Spirit, whom the Father will send in my name, will teach you everything, and will cause you to remember everything I said to you."
Should I accept your opinion or what the Bible clearly says?
My opinion is that the Bible clearly indicates who Jesus is talking to. The first clue is found in the first 8 verses of John 14. Jesus is talking to His Apostles and no one else. So I checked back to John 13. There are no representatives of anyone else. Just Apostles.
Who is the
"man of God" in @ Tim. 3:17? Scripture defines them as:
A) called directly by God followed by signs and wonders, or:
B) an Apostle or one who is ordained by the Church.
That anyone with a Bible and no ecclesiology can declare themselves a "man of God" is not supported in Scripture. It's a man made tradition. Key in any Bible search engine you like: "man of God" and see the usage for yourself.
"All scripture is inspired by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work." (2 Tim. 3:16-17)
There is the relationship: the Scriptures are a tool for "teaching, for reproof, for correction, and for training in righteousness," but who is to use this tool for these purposes? That is, who has the authority to teach, reproof, correct, and train others in righteousness? The "man of God" has this authority.
But, who is the "man of God?" You may wish to claim this title for yourself as well, but a short survey of Scripture's use of the title will reveal that this, too, is a privileged title that cannot be simply taken upon oneself:
Moses - "This is the blessing with which Moses the man of God blessed the children of Israel before his death." (Deut. 33:1)
"Then the people of Judah came to Joshua at Gilgal; and Caleb the son of Jephunneh the Kenizzite said to him, 'You know what the LORD said to Moses the man of God in Kadesh-barnea concerning you and me.'" (Josh. 14:6)
The Angel of the Lord - "Then the woman came and told her husband, 'A man of God came to me, and his countenance was like the countenance of the angel of God, very terrible; I did not ask him whence he was, and he did not tell me his name...' Then Manoah entreated the LORD, and said, 'O, LORD, I pray thee, let the man of God whom thou didst send come again to us, and teach us what we are to do with the boy that will be born.'" (Jud. 13:6, 8)
Samuel - "The servant answered Saul again, 'Here, I have with me the fourth part of a shekel of silver, and I will give it to the man of God, to tell us our way.'" (1 Sam. 9:8)
Elijah - "And she said to Elijah, 'What have you against me, O man of God? You have come to me to bring my sin to remembrance, and to cause the death of my son!'" (1 Kings 17:18)
Elisha - "And she went up and laid him on the bed of the man of God, and shut the door upon him, and went out... When Elisha came into the house, he saw the child lying dead on his bed." (2 Kings 4:21, 32)
David - "According to the ordinance of David his father, he appointed the divisions of the priests for their service, and the Levites for their offices of praise and ministry before the priests as the duty of each day required, and the gatekeepers in their divisions for the several gates; for so David the man of God had commanded." (2 Chr. 8:14)
St. Timothy - "But as for you, man of God, shun all this; aim at righteousness, godliness, faith, love, steadfastness, gentleness." (1 Tim. 6:11)
Contrary to the opinion that the "man of God" can be any Christian without distinction, Scripture itself will not allow such an interpretation, insisting that the "man of God" is a figure of authority, either commissioned by God directly through Divine Intervention (such as Moses or the Angel), or appointed by another holder of authority (such as Samuel, David, Elisha, and St. Timothy).
From this very brief survey of the phrase "man of God" (there are perhaps a dozen or so more passages, relating to the characters listed above - I have chosen representative verses), we see that what holds true for "pastors" holds true for the "man of God": it is a title of authority that can in no way be taken upon oneself, but rather, it is bestowed upon a man by a higher authority. A man must be called by God to hold this title of "man of God."
But there is another objection here: you will say, "I have been called by God to be a pastor." Very well, let us take another look at Scripture to measure your claim.
Biblically, there is only one way to become a legitimate ambassador of Christ, or "pastor": by appointment from a superior. This can be done in two ways: being commissioned by a legitimate ambassador (apostolic succession), or being called directly by God. We saw examples of this in Scripture already: Ss. Timothy and Titus were appointed to their positions of authority by succession, Moses was appointed to his position directly by God, with no human mediation.
As to the first method, apostolic succession comes through the laying on of hands in ceremony: "Hence I remind you to rekindle the gift of God that is within you through the laying on of my hands... guard the truth that has been entrusted to you by the Holy Spirit who dwells within us." (2 Tim. 1:6, 14)
When St. Paul imposed his hands on St. Timothy, he passed on a legitimate apostolic authority, "entrusted" the "truth" to him, and imparted the gift of "the Holy Spirit" for the safekeeping and preservation of the Gospel.
As has already been said, only a superior can do this, and not an inferior, since an inferior cannot pass on what he does not already possess.
By What Authority? A Challenge to Protestant Pastors
Laying on of hands is a ritual.