Modern Christianity is sometimes attacked as a religion that has become corrupted over the centuries. Today's Christianity, it is said, has evolved from single-celled religious beliefs of the first centuries after Christ.
Hilary of Poitiers was born at Poitiers, France either at the end of the 3rd or beginning of the 4th century A.D. Below are his writing in defense of the Scripture truth that Jesus of Nazareth is the eternal Son of God. His writing demonstrates that orthodox Christian teaching about Jesus' divinity then is the same as orthodox Christian teaching today.
God gave his Son
In a debate, Hilary uses John 3:16 and the term only-begotten (one and only, NIV) to provide a foundation for trusting Jesus is the eternal God who became a human being in order to win our forgiveness.
First let us see whether the word means, as you assert, a perfect creature of God: Only-begotten being equivalent to perfect, and Son a synonym for creature.
John described the Only-begotten Son as God, not as a perfect creature.
His words, “Which is in the bosom of the Father" [John 1:18], show that he anticipated these blasphemous designations. Indeed, he had heard his Lord say, “For God so loved the world that He gave His Only-begotten Son, that whoever believes in Him should not perish but have everlasting life.”
No worthless gift
God, who loved the world, gave his Only-begotten Son as a manifest token of his love. If the evidence of his love is this, that he
bestowed a creature upon creatures,
gave a worldly being on the world’s behalf,
granted one raised up from nothing for the redemption of objects equally raised up from nothing,
this cheap and petty sacrifice is a poor assurance of His favor toward us.
A gift of immeasurable price
Gifts of price are the evidence of affection, the greatness of the surrender of the greatness of the love.
God, who loved the world, gave not an adopted Son, but his own, his Only-begotten. Here is personal interest, true sonship, sincerity; not creation or adoption or pretense. Herein is the proof of his love and affection, that he gave his own, his Only-begotten Son.