Orthodox Christian Religions
Traditionally, most Orthodox religions do not require public vows from the couple. It is assumed that they already have an understanding with each other. As such, many of these churches' wedding ceremonies are set in stone with little room for originality. But it's still worth asking your priest if you can include some of your own sentiments.
Greek Orthodox marriage does not unite a couple. Its role is to recognize a union that God has already made. Thus, marriage is more than a legal contract. There are no vows because the man and woman are assumed to have already committed to one another and welcomed God's presence in their marriage. There is no “till death do us part.” Christ destroyed death by His resurrection. Ergo, the union of the man and woman in Christ is eternal.
In the Russian tradition, vows can be spoken aloud.
I, ____, take you, ____, as my wedded wife/husband and I promise you love, honor, and respect; to be faithful to you, and not to forsake you until death do us part. So help me God, one in the Holy Trinity, and all the saints.