The very first prophecy in the Bible is revealing. It reveals a person who is coming, who is a male, which means He would be coming into humanity itself to rescue it. There is so much in this first prophecy in seed form. God can say so much in few words! The passage I have in mind is Genesis 3:15.

“And I will put enmity between you and the woman, and between your seed and her seed, He shall bruise your head, and you shall bruise his heel.”

Upon first reading, this passage may not be considered as a proof or an evidence for the support of a Trinity but I believe it is. We have a second person spoken about by God, who would become a man, be born into this world through a woman, who would reverse all the curse brought in by the fall, and recover and rescue humanity from its own demise. To do this, it was necessary that He would walk with us, becoming a part of us. The Son Of God was clothed in the very nature He was going to rescue and redeem. This was necessary, for when humanity was lifted up in Him to the right hand of the Father, it was as if all redeemed humanity was lifted up with Him.

The first prophecy was spoken by God, directly to the ancient serpent, in the hearing of Adam and Eve. For the listeners, it would mean something different. For the Serpent, this would be his judgment and condemnation. For Adam and Eve, it brought them great comfort, that despite their high treason and rebellion, of which this world has bore the ugly fruit of, ever since, God had and would put their sin away, and in the end, completely reverse everything that had been done.