Are weddings biblical?

Let's begin by considering the God who performed the first ever wedding.

Though there is one God (Deut. 6:4), he is three persons. In context, even the word "one" in Deuteronomy 6:4 means one, as in a bunch of grapes. The plural form of God (Elohim) is used to refer to the Creator in Genesis 1:1 and throughout the rest of the narrative. So, this is consistent with the doctrine of the Trinity. Genesis 1:26 states, “Then God said, “Let us make man in our image, after our likeness. And let them have dominion over the fish of the sea and over the birds of the heavens and over the livestock and over all the earth and over every creeping thing that creeps on the earth.” The plural words “us” and “our” refer to God. Regarding Jesus Paul wrote, “For by him all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities—all things were created through him and for him. And he is before all things, and in him all things hold together” (Col. 1:16-17).

The entire Trinity which includes the second person, the Son, was present at creation (cf. Gen. 1:1-2; Psa. 33:6,9; John 1:1-3; Eph. 3:9, etc.). And at creation when the woman, later named Eve (Gen. 3:20), was created, brought to and united with Adam as his wife (Gen. 2:22-25), the Son of God was present. Jesus not only officiated over the first wedding, but he literally made all biblical weddings possible in the first place (cf. Gen. 2:18).

Jesus’ first miracle of turning water into wine (John 2:3, 6-11) was at a wedding (John 2:1-2), and he included weddings as illustrations in some of his parables (Matt. 22:1-14; 25:1-13; Luke 12:35-40; 14:7-11). Paul describes Jesus as the husband of his bride (Eph. 5:23-24, 25-30, 31-33). We read of the marriage supper of the Lamb (Jesus) in Revelation 19:6-10, and weddings are described or alluded to in other locations in the Bible (Gen. 29:21-30; Psa. 45:10-15; Song 3:11-11, cf. Malachi 2:14-15; Isaiah 54:5; Mark 10:9, etc.). And historically the church has celebrated such great marriage moments. So, yes, weddings may be biblical.

On the other hand, believers shouldn't marry unbelievers (cf. 2 Cor. 6:14) and covenant marriage requires a specific form of union before God, i.e., one man and one woman (Gen. 2:24). So, not all marriages, and therefore weddings, are biblical. Abraham Lincoln once posed the question, “If you call a dog’s tail a leg, how many legs does a dog have?” “Five,” his audience would invariably answer. He politely responded, “No, the correct answer is four. Calling a tail a leg does not make it a leg.” [1] So, in particular, though they may be called such and even officiated over by some type of clergy, weddings that are not between one man and one woman aren’t biblical.

Reference

[1] Above is how I originally heard the quote. There are different versions of it some using a calf, a horse, a pig and even a sheep as an example. For one version of it, please see: Rice, Allen Thorndike, Editor. Reminiscences of Abraham Lincoln by Distinguished Men of His Time. Kessinger Publishing, LLC (2005).