In Mark 2:18-20 we find Jesus explaining to interlocutors why his disciples do not fast. He says:
Can the wedding guests fast while the bridegroom is with them? As long as they have the bridegroom with them they cannot fast. But the days will come when the bridegroom is taken away from them and then they will fast on that day.
Jesus refers to himself as a bridegroom and his disciples the guests of a wedding feast. Behind this use of a wedding metaphor is the conviction that the situation of the disciples with Jesus is that of Israel's eschatological wedding with Yahweh (cf. Hosea 2:16ff). The in-breaking of the joys of the end-times has occured in Jesus with his disciples.
The bridegroom metaphor used to describe the person of Jesus is already present in the references of John the Baptist about Jesus. In Mark 1:7 the Baptist describes his relationship with the One coming after him in these words: "I am not worthy to stoop down and untie his sandal straps.". The allussion is to the succession of go'el's (a go'el is a redeemer) in a levirate marriage. The classic example of this kind of succession is found in the book of Ruth.
Boaz wanted to "redeem" the lineage of Naomi's husband, by marrying Ruth, the childless daughter-in-law. But he was not the kinsman who had the rights of redemption. He therefore goes to the elders and engages the rightful go'el in a process wherein this latter would hand on to him the right to redeem. At the end of this judicial transaction, the go'el formally surrenders his rights of redemption to Boaz. To seal this agreement, the go'el takes off his sandal and gives it to Boaz.
Now it used to be a custom in Israel that, to make binding a contract of redemption or exchange, one party would take off his sandal and give it to the other. This was the form of attestation in Israel. So the near relative ('the goel'), in saying to Boaz "Acquire it for yourself" drew off his sandal. (Ruth 4:7)
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John the Baptist's mention then of his unworthiness to untie the sandal straps of Jesus is an allussion to the rights of Jesus as Redeemer of Israel and as a bridegroom whose place he cannot take.
In John 3:29, John the Baptist refers to himself as the bridegroom's friend -- the best man, so to speak -- in a wedding where Jesus is the groom
The one who has the bride is the bridegroom; the best man, who stands and listens for him, rejoices greatly at the bridegroom's voice. So this joy of mine has been made complete. He must increase; I must decrease.
In Paul, the clearest reference to Christ as the groom of the Church, His Bride is in Ephesians 5:25-31. Here he exhorts husbands to love their wives as Christ loves the Church
Handing himself over for her to sanctify her, cleansing her by the bath of water with the word, that He might present to himself the Church in splendor, without spot nor wrinkle or any such thing, that she might be holy and without blemish. (Eph. 5:25-27)
Even Paul alludes to himself as the one who "bethrothed" the Corinthian Church "to one husband ... Christ" (cf. 11:2).
Finally, in the book of Revelation, Christ is the Lamb who weds the New Jerusalem and in whose honor the wedding feast of the last day is celebrated. (Rev. 19:6-9).
