1. This question goes beyond the mere usage of words. There is Son and there is son. Son by title (or mere designation) is not the same as son by adoption; neither of which are the same as son by creation; and none of the above are the same as Son - only begotten.
2. This question goes to the heart of all that is professed as Christianity. The Christian gospel declares that God so loved... that He gave His only begotten Son (John 3:16). The measure of God’s love for humanity is manifested in the gift of His only begotten Son (1John 4:9). If, therefore, Jesus Christ is not, truly, the only begotten Son of God, then God did not sacrifice as much as is presented to us; and if He did not sacrifice as much, then , He did not so love after all.
3. So critical is this issue that it determines who is antichrist. "He is antichrist, that denieth the Father and the Son." 1 John 2:22.
4. The Scriptures are absolutely clear that Jesus Christ is the only begotten Son of God. Jesus declared "I proceeded forth and came from God." John 8: 42. Of Christ, "the wisdom of God" (1 Cor. 1:24) it is also declared: "The Lord possessed me in the beginning of his way.... When there were no depths, I was brought forth.... Then I was by him, as one brought up with him: and I was daily his delight, rejoicing always before him. Prov. 8:22-24, 30.
5. The vast majority of professed Christians deny that Jesus Christ was truly begotten of God before He came into the world as a babe. By the belief that God is a Trinity, persons deny that Jesus Christ is the begotten Son of God and that JEHOVAH is the Father of Jesus Christ.
6. Prophets of the Bible have referred to the Father as "the God and Father of our Lord Jesus Christ" (1 Pet. 1:3; 2 Cor. 11:31).
7. The Trinity declares that there is one God, a single Being who is simultaneously Father, Son and Holy Spirit. This idea immediately creates confusion as to who is the God that gave His Son and who was the Son that was given. Indeed, it raises a question as to whether it was really a Son that was given. This is nothing else but "denying the only Lord God, and our Lord Jesus Christ" (Jude 4) against which we have been warned.
8. Furthermore, if God is a Trinity and Jesus Christ is, therefore, himself the Supreme Being or he is co-equal with the Supreme Being, then it implies that Jesus did not truly die. The Supreme Being is described as the one "Who only hath immortality, dwelling in the light which no man can approach unto; whom no man hath seen, nor can see." 1Tim. 6:15,16. If such applied to Jesus then he did not truly die, but was very much alive while foisting a delusion on humanity, thus making all our professions about the death and resurrection of Christ mere vanity and illusion.
9. The Bible is clear as to who is the One God. "But to us there is but one God, the Father" (1 Cor. 8:6).
10. The Bible is clear as to who is the only begotten Son of the One God; "and truly our fellowship is with the Father, and with His Son Jesus Christ" (1 John 1:3).
11. The Bible is clear that the Spirit of God, the Holy Spirit, is related to God in the same way that the spirit of man is related to man; "For what man knoweth the things of a man, save the spirit of man which is in him? Even sothe things of God knoweth no man, but the Spirit of God" (1 Cor. 2:11). The Holy Spirit is therefore not an inanimate force; neither is the Holy Spirit a distinct and separate consciousness from JEHOVAH Himself. Rather, the Holy Spirit is an integral aspect of JEHOVAH’S own being. Hence, when one grieves the Holy Spirit, it is JEHOVAH Himself that is grieved and not someone else.
12. The Bible is clear as to who are the only two Beings in the universe to whom worship is due; "And I saw no temple therein: for the Lord God Almighty and the Lamb are the temple of it." Rev. 21:22. It is clear that the Lord God Almighty is not the same Being as the Lamb, even though the Lamb is worshipped alongside the Lord God Almighty. The reason for this is that the Lamb is the only begotten Son of the Lord God Almighty and it is the will of the Father that His Son should likewise be worshipped; John 5:22, 23.
13. JEHOVAH is divine. His only begotten Son could not be other than divine also. "……the great mistake of Trinitarians, in arguing this subject is this: they make no distinction between a denial of a Trinity and a denial of the divinity of Christ. They see only the two extremes, between which the truth lies; and take every expression referring to the pre-existence of Christ as evidence of a Trinity. The Scriptures abundantly teach the pre-existence of Christ and his divinity; but they are entirely silent in regard to a trinity" -J.H. Waggoner, Review and Herald. Nov.10, 1863.
14. God has used what is undoubtedly one of the closest and most endearing of human relationships - that of parent and offspring - to define the relationship between Himself and His only begotten Son, Jesus Christ. But human beings have presumptuously undertaken to speculate in relation to God, describing the relationship as a Trinity and promulgating such human philosophy as giving a more accurate description than that which God himself has chosen to give. In the process the gospel of salvation is distorted and made obscure.
15. It is only a degraded concept of JEHOVAH that leads individuals to think that it is somehow demeaning to Jesus Christ to be the literal Son of the Supreme Being.
16. The Bible is clear that even after an end is put to sin "then shall the Son also himself be subject unto him that put all things under him, that God may be all in all." 1Cor. 15:28.
17. Must the selflessness and benevolence of the Great JEHOVAH in exalting His Son to full equality with Himself, giving Him a place on His own throne (Rev. 3:21), giving Him all authority and power (Matt. 28:18) and giving Him JEHOVAH’S own name (Ex. 23:20, 21; Phil. 2:9; Heb.1:4) ) be used as a means of detracting from JEHOVAH in declaring that Jesus Christ is too exalted to be JEHOVAH’S own Son? God forbid! Such is the highest evidence that God is love (1 John 4:8), because it is out of love for His own Son that He has done all this. Yet He has spared not His own Son, but has delivered Him up for us all (Rom. 8:32), because of His great love for us also, that we might be adopted as sons and daughters of His, to be joint heirs with His only begotten Son (Rom. 8:17). Marvel 0 heavens!
18. Jesus Christ is indeed worthy of adoration and honour because, while he could have perverted His powers and endowments as Lucifer did, He did not. He has humbled Himself and submitted to His Father without reserve, being drawn to love His Father even more. Jesus Christ is truly great, and His greatness is most evident in His submission to His Father. Only a true Sonwould so single-heartedly love, adore and submit to His Father in the face of His Father so unselfishly and unreservedly exalting Him.
19. Jesus is truly the Son of God. Upon this rock the Church is built and the gates of hell will not prevail against it. Matt. 16:16-18. "Who is he that overcometh the world, but he that believeth that Jesus is the Son of God?" 1 John 5:5.
20. Be not deceived. Our assurance that God loves us is that God gave His only begotten Son whom He loves, in order to save us. "He that spared not his own Son, but delivered him up for us all, how shall he not with him also freely give us all things?" Rom. 8:32. God has even offered to make us partakers of the divine nature (2 Pet. 1:4) by offering us His Holy Spirit, an integral aspect of JEHOVAH’S own Being. What marvellous love ! As the songwriter says "Love so amazing, so divine, demands my life, my soul, my all"