Today again, I found someone asking this very question.
We know that Jesus Christ is the same yesterday, today, and forever.
Then did the figures of the Old Testament Abraham, Isaac, Jacob, Joseph,
and the prophets believe in the Trinity? What did they believe?
They believed in the one and only God; so then, did they all go to hell?
If the Trinity is the truth today, what happens to them?
Countless Protestant pastors and Catholic priests say that if one does not believe in the Trinity, one is a heretic.
They are blind and do not know the correct answer found in Scripture.
And they are calling all the prophets of faith heretics,
because they do not know the Trinitarian god.
Below is the correct answer to someone’s question.
“You shall utterly destroy anyone who sacrifices to any god other than the Yehowah alone.” (Exodus 22:20)
“If you believed Moses, you would believe Me, for he wrote about Me.” (John 5:46)
“And beginning with Moses and all the Prophets, He explained to them
what was said in all the Scriptures concerning Himself.” (Luke 24:27)
“You are My witnesses,” declares the Yehowah, “and My servant whom I have chosen,
so that you may know and believe Me and understand that I am He.
Before Me no god was formed, nor will there be one after Me.
I, even I, am the Yehowah, and apart from Me there is no savior.” (Isaiah 43:10–11)
“For thus says the Yehowah, who created the heavens—He is God;
who formed the earth and made it, He established it;
He did not create it to be empty, but formed it to be inhabited
‘I am the Yehowah, and there is no other.’” (Isaiah 45:18)
“For to us a child is born, to us a son is given; and the government shall be upon His shoulder,
and His name shall be called Wonderful Counselor, Mighty God,
Everlasting Father, Prince of Peace.” (Isaiah 9:6)
“Therefore I said to you that you will die in your sins;
for unless you believe that I am He, you will die in your sins.”
So they said to Him, “Who are You?”
Jesus said to them, “Just what I have been telling you from the beginning.” (John 8:24–25)
“He will swallow up death forever; and the Yehowah God will wipe away tears from all faces,
and the reproach of His people He will take away from all the earth,
for the Yehowas has spoken.” (Isaiah 25:8)