If you belong to either a Catholic or Orthodox religious identity, don’t read this. You’ll hate it.
The definition of the term “sacrament” is a religious ritual that serves as a means of grace. There is no such thing. Nothing in this world is a means of grace. Grace is not that kind of thing. Grace is the process of spiritual adoption, of divine election. No ritual can aid that process. Grace/election either happens or it does not. God chooses; the initiative is totally in His hands. He puts His grace on you at His whim. You cannot engage any ritual to get grace.
Ritual has no power. Ritual can only express the power that is already there. Any ritual will do, so long as it meets your convictions. One of the biggest lies of the institutional churches is that this or that particular historic institution descends directly from the Apostles, and all the leadership insists that all the man-made crap they’ve developed over the centuries is demanded by God. Go ahead; keep saying that. Meanwhile, God is working elsewhere. You are lying — lying to yourself first and foremost. Worse, you are insulting God and it won’t go well when you stand before Him.
In particular, the notion that marriage should be a sacrament is a lie from Hell. I cannot call you a fellow Christian if that’s what you say. Marriage is a covenant ordained by God. For those who think a covenant bears any resemblance to a contract, you are standing outside of Christ. You cannot come to Christ without His Covenant. Everything we do under His authority is part of the Covenant, and so marriage is a covenant in the Bible. Any use of the word “sacrament” is inherently anti-Christian because it goes against Scripture. We cannot walk together if you use that word or concept.
There is no room for discussion or debate. This is where I stand.