John 3:16 says, “For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.” The importance of the words “only begotten” is to declare the eternal generation of the Son. It is inaccurate to translate this name of Jesus as God’s “only Son” by omitting “begotten.” We must distinguish between the believer’s sonship with the Father by adoption and Jesus’ Sonship by “eternal generation;” thus, the words “only begotten Son” are absolutely necessary to describe the Biblical relationship of the Son to His Father.
Without doubt, “John 3:16 is quoted more than any other verse in the Bible, at least by Christians and other church-goers. There may be no verse that is more frequently perverted than this one, but most people still know the full verse as presented . . . Why then, is it so hard to find the word ‘begotten’ in other versions? (such as the ESV) The Greek word in question is ‘monogenes.’ This is a compound of two Greek words ‘monos’ and ‘genes,’ the latter being drawn from the verb ‘genao,’ which means to beget or cause to be produced. ‘Monos’ means only or single, as is clear by its many appearances in English, such as monotony, monopoly, monotone, etc. ‘Genao’ has come into the English language as well in words like generation, genesis, genes, generate, and so forth. The two words together mean ‘only begotten!’ It could not possibly mean anything else. In spite of this obvious, uncontestable, and invariable meaning, it is perverted with great frequency. The perversion of this verse appears to have begun, not with Christians, but with Gnostics in Egypt. These Gnostics not only denied the nature of Christ, but rewrote much of the New Testament in order to pervert the truth.” ~ John Hinton, Ph.D