What is the name of God? He revealed His name in the Hebrew Bible as YHVH. We call that the Tetragrammaton, which means, the "four letters". The corresponding letters in the English alphabet would be YHWH, or JHVH. We would pronounce God’s name as Yahveh, Yahweh, or Jehova, but those are only guesses since the Tetragrammaton has no vowels. William Branham had a problem with the literal name of God. Twice in 1957, once in 1960, and once in 1963 he said the name of God was JVHU. He never correctly identified God by the biblical Tetragrammaton. Of all people, one would think a prophet of the LORD would get God's name right.
Is that a form of taking God’s name in vain? Or is it perhaps a form of blasphemy? I don’t know. In any case, I don’t believe WMB was ever guilty of using God’s name as so many do today by saying OMG (at least not on tape). I'm sure he didn't use His name as a swear word. I don’t know that he ever made a flippant oath by His name. But he did do something very serious, so serious that it could be considered outright blasphemy.
William Branham said “thus saith the Lord” on many occasions when the Lord didn’t say what WMB said He did. Every time WMB made a prophecy, punctuating it with, “thus saith the Lord,” and it failed to come to pass exactly as predicted, he used God’s name in vain. Every time he predicted anything in the name of the Lord and it failed to come to pass, he tarnished the name of God. Every time WMB taught something that he said came from the Bible when it didn’t (such as Serpent’s Seed) he was attributing that false teaching to the Holy Spirit who taught no such thing. Everything WMB predicted, taught, or said in his role as a prophet of God which deviated in any way from the truth was a slander against God, a horrendous misuse of God’s name. In short, William Branham demonstrated a most serious way to use God’s name in vain every time he practiced his self-proclaimed authority as a prophet.
Read Jeremiah 23. The entire chapter is an indictment against prophets like WMB. I will quote just a portion where Jeremiah speaks for the LORD:
"I have heard what the prophets have said who prophesy falsely in My name, saying, ‘I had a dream, I had a dream!’ How long? Is there anything in the hearts of the prophets who prophesy falsehood, even these prophets of the deception of their own heart, who intend to make My people forget My name by their dreams which they relate to one another, just as their fathers forgot My name because of Baal? The prophet who has a dream may relate his dream, but let him who has My word speak My word in truth. What does straw have in common with grain?” declares the Lord. “Is not My word like fire?” declares the Lord, “and like a hammer which shatters a rock? Therefore behold, I am against the prophets,” declares the Lord, “who steal My words from each other [as WMB did from false prophets such as Charles Taze Russell, Joseph Smith, Edgar Cayce and others]. Behold, I am against the prophets,” declares the Lord, “who use their tongues and declare, ‘The Lord declares [in other words, “thus saith the Lord].’ Behold, I am against those who have prophesied false dreams,” declares the Lord, “and related them and led My people astray by their falsehoods and reckless boasting; yet I did not send them or command them, nor do they furnish this people the slightest benefit,” declares the Lord.