Up to this point in the Gospel of John, John the Baptist has consistently been pointing others to the Messiah, the Lamb of God–Jesus Christ. However, what sticks out in John 3:27-30 is that John is not only one who understands it’s his entire purpose in life to point others to Christ, but he finds utter joy because others are going to Christ, while departing from him.
This is brought out in the final part of v.29 where John transitions out of the wedding analogy to articulate his own personal testimony. Because John is hearing the voice of the bridegroom, the joy he possesses—this joy completely centered on the exaltation of Christ—has been completed. This is not a passing joy that he experienced on a really pleasant day. No, this is a joy that began in the past, but continues on.
So John doesn’t just quietly resign himself to what is happening with Jesus, but instead it causes him to be in a state of complete joy! So is Christ getting all the glory the top priority in your life? Is that an acceptable accomplishment in your mind, regardless of what, if any, human element is recognized? We have been redeemed, not to seek our own glory, but in order that he might receive praise for the glory of his grace (Eph. 1:3-14).