Swearing oaths is something that is usually done in a legal context in which God is invoked to further solidify the import of avoiding bearing false witness. In a courtroom, to swear an oath is to swear allegiance to the law, the truth and to God. Marriage vows are public statements made for public consumption among one's peers (family, friends). I agree with you,
@Asforme&myhouse, that marriage vows are not scriptural, but I don't see the context Matthew 5:33-37 to definitively indicate that the oaths being discussed in that section of the Sermon on the Mount to be wedding vows. The preceding verses discuss treacherous divorce, and the subsequent verses discuss turning the other cheek; how would marriage vows bridge the gap between divorce and turning the other cheek? To the extent that either would relate, it would seem that Christ could have been introducing the solemnity of oaths relating to marriage by mentioning the dire consequences of treacherously
ending a marriage, but, again, that would only reinforce the importance of keeping marital promises rather than being a proof for refraining from making oaths or covenants. The point has been made by many here that covenants should be kept to a minimum but to include covering of the wife on the part of the husband and sexual fidelity to the husband on the part of the wife.
All I was attempting to assert in my earlier post was that I see no scriptural basis for swearing allegiance or announcing covenants before either State or Church, because I see them as having no authority over our relationships. Please don't conflate 'Church' with 'God.' Covenants made with or before God can be done so privately, just as we are exhorted to do with our prayer life. Again, as
others have already effectively articulated, Scripture does not indicate that these vows are to be licensed or regulated by the State or the Church. Nor is there any requirement that vows must be publicly announced. Such practices seek to acquire approval from the world rather than approval from our Father.