Trinity
This is an exhert from the Jack Van Impe website. Just refer to the scriptures.
The moderator of a radio call-in program in Illinois had Dr. Van Impe for a guest. He hated Christianity and claimed to believe only the Old Testament. When the broadcast started, he announced that even though this was a call-in show, he would accept no calls from listeners because he wanted to use the entire hour to tear the evangelist to shreds. He started his tirade by saying, "I can't accept the three-headed God of Christians." In other words, he rejected and mocked the Trinity.
"Well, sir," said Jack, "since you believe only the Old Testament, I'll show you what that part of the Bible has to say about the Trinity."
Beginning then at Genesis 1:1 and showing that the very first mention of God is given in the plural Hebrew word Elohim, he moved through the Old Testament revealing the truth about the Trinity.
He pointed out that the plural word for God (Elohim), was used again at the creation of man (see Genesis 1:26), the Lord has a Son (see Proverbs 30:4), that the Lord speaks to the Lord (see Psalm 110:1), and that the Lord spoke of sending the Lord to the earth (see Zechariah 2:10,11).
At that point, the distressed disc jockey decided it was time to open the program to the calls of listeners.
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Also in Genesis
Genesis 1:26
And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.
Genesis 11:7
Go to, let us go down, and there confound their language, that they may not understand one another's speech.
Let US, Let US. In Genesis 1:26 he's not talking to the angels for the bible describes the angels as looking different from man in size and etc.
Daniel 3:25
He answered and said, Lo, I see four men loose, walking in the midst of the fire, and they have no hurt; and the form of the fourth is like the Son of God.
God the father, the son and the holy ghost have always been. THEY being one God of one spirit amnifested in three divine persons. How big God is!