Almighty God is God the Father, God the Son, and God the Holy Spirit - yet the Holy Three are ONE. They are also eternal - no beginning and no ending. God began to describe His nature all the way back in Genesis:
Genesis 1:26-28 KJV 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. 27 So God created man in his own image, in the image of God created he him; male and female created he them. 28 And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.
Genesis 2:7 KJV And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.
Please take special note of Genesis 1:26 where God speaks of "our image" - indicating plural. Almighty God has been a Holy Trinity for eternity past and will be for eternity future. God the Son was made manifest in the flesh as Jesus Christ, but He was still God the Son - fully man and fully God. Jesus Christ was also The Word and Creator:
John 1:1-3 KJV In the beginning was the Word, and the Word was with God, and the Word was God. 2. The same was in the beginning with God. 3. All things were made by him; and without him was not any thing made that was made.
Jesus Christ was God with us during His earthly ministry:
Matthew 1:21-25 KJV And she shall bring forth a son, and thou shalt call his name JESUS: for he shall save his people from their sins. 22. Now all this was done, that it might be fulfilled which was spoken of the Lord by the prophet, saying, 23. Behold, a virgin shall be with child, and shall bring forth a son, and they shall call his name Emmanuel, which being interpreted is, God with us. 24. Then Joseph being raised from sleep did as the angel of the Lord had bidden him, and took unto him his wife: 25. And knew her not till she had brought forth her firstborn son: and he called his name JESUS.
See my blogs for many Scriptures that prove Jesus Christ was and is God - God the Son, ONE with God the Father and God the Holy Spirit. Jesus Christ is no longer in the flesh - sitting at the right hand of God the Father in Heaven. It is NOT a small or insignificant matter to deny the absolute deity of Jesus Christ:
Matthew 10:32-33 KJV Whosoever therefore shall confess me before men, him will I confess also before my Father which is in heaven. 33. But whosoever shall deny me before men, him will I also deny before my Father which is in heaven.