"God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets," (Hebrews 1:1 KJV)
""The rain and snow come down from the heavens and stay on the ground to water the earth. They cause the grain to grow, producing seed for the farmer and bread for the hungry. It is the same with my word. I send it out, and it always produces fruit. It will accomplish all I want it to, and it will prosper everywhere I send it."" (Isaiah 55:10-11 NLT)
One of the first things I learned about in my New Life with Christ, was how to express the fact that Jesus has always been, from the very beginning! We discover this clearly in the Revelation 22:12, as Jesus testifies to the eternity of His existence, saying, "Look, I am coming soon, bringing my reward with me to repay all people according to their deeds. I am the Alpha and the Omega, the First and the Last, the Beginning and the End."
Whether you can accept it or not, it is written without there being a question of who; if there be any question, the only one would be how? There are people that question the existence of Jesus before He was born in Bethlehem, that glorious morning as if His birth was His beginning; but we know from the Holy Scriptures that He is the eternal God, who's beginning was always the Word! When God spoke, the Word existed; therefore, we have no need to wonder how, but only to believe that it is so.
Secondly, there are some that believe Jesus did not actually come in the flesh, as if He was some sort of fathom or just a spirit that did not actually have a birth, but manifested. This might seem hard to believe, but Mary was a virgin, and Jesus was formed in her womb, just as any normal baby; except His life was produced by the Holy Spirit.
Imagine why this was very important! Man needed to be redeemed by a Man, but not just any Man, but one that was born of the Spirit...
"Dear friends, do not believe everyone who claims to speak by the Spirit. You must test them to see if the spirit they have comes from God. For there are many false prophets in the world. This is how we know if they have the Spirit of God: If a person claiming to be a prophet acknowledges that Jesus came in a real body, that person has the Spirit of God. But if someone claims to be a prophet and does not acknowledge the truth about Jesus, that person is not from God. Such a person has the spirit of the Antichrist, which you heard is coming into the world and indeed is already here." (1 John 4:1-3 NLT)