18 No one has seen God at any time. The only begotten Son, who is in the bosom of the Father, He has declared Him.
The only begotten Son [“God” in some manuscripts rather than “Son”],
Once again the Holy Spirit characterizes the Son as the one and only Son. The Son is completely unique; no one is like Him. This is the same Greek word as in verse 14. Christ was the unique Son to the Father; no one else was like Him. He was totally exceptional. Moses did not have this kind of relationship with the Father, but only Jesus.
“Only begotten” does not imply physical generation but goes back to the Son’s eternal fellowship with the Father.
If the Nestle’s Greek text is right, then this phrase should read “the only begotten God.” If so, then this is a fitting conclusion to the prologue, which has argued for the deity of Christ. Whether “God” or “Son” is correct, both refer to the deity of Christ.
who is in the bosom of the Father,
Christ was preexistent with the Father. He had a close relationship for eternity, for He was at the Father’s side. They had an eternally active relationship.
He [emphatic] has declared [explained] Him.
The word “declared” is explained, interpreted, expounded or exegeted. We get the English word “exegeted” from this verb (exegeomai). Christ interpreted the Father; He exegeted Him while on earth. He gave a full account of the Father. This does not mean there is nothing more to learn about the Father but that, to the degree that Christ revealed the Father, it is true of the Father. The Son’s interpretation of God is final and full.
The “He” is emphatic because only Christ can declare the Father properly.
The Word bridged the gap between God and man.
Christ explained God and He is also the explanation of God (Jn 14:7-9). The reason Jesus was able to overcome the enormous gulf between God and man is that He was the one-of-a-kind Son. His incarnation interpreted and gave a full account of His relationship to the Father. There is an adequate revelation made in who and what Christ is. God is exactly what Christ revealed Him to be.