Summary: Churches need to get out of the marriage business. It is a tradition, not a biblical mandate. Stick to mission!
21 And the LORD God caused a deep sleep to fall upon Adam, and he slept: and he took one of his ribs, and closed up the flesh instead thereof;
22 And the rib, which the LORD God had taken from man, made He a woman, and brought her unto the man.
23 And Adam said, This is now bone of my bones, and flesh of my flesh: she shall be called Woman, because she was taken out of Man.
24 Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh.
No big ceremony or a license needed or even implied here. Simplicity is awesome. Man made it more complicated. For centuries it was just a contract between families and sometimes a spoils of war situation. Neither government nor church was involved with it unless you were a member of the royal family looking for a spouse.
Everyone has gone crazy over the SCOTUS decision. You prayed, you voted and now you just hand it over to God. Brethren, don't do weddings anymore and you need not worry about polygamy, polyandry or anything else.
It is the Government's license whereby you obtain government benefits so allow agents of the government to execute and certify the license. When you say, "By the power invested in me by the State of _____" you are acting as an agent of the State and should follow the laws of the State. Disagree with those laws? Then resign as an agent of the State. It seems very simple to me.
There is nothing in Scripture about the church doing weddings with a pastor as the officiant. It was bad theology around the eighth century that started the whole tradition. Dump tradition and stay on mission as dictated in Matt 28:19.20 and Ephesians 4:11-16. Let the Justice of the Peace do the license part and let the couple say their vows before God and family sans preacher and building like it was done for millennia before the eighth century. If they need a building they can rent a building like the Legion, Elks or whatever. Do it in the park or the backyard even in a barn having a dance afterward. Location is not important to God, only man.
God does not require a license and marriage is official with Him when they "become one flesh." Even a one night stand is considered a one flesh relationship. (1 Cor 6:15, 16) That means there are already a large number of polygamists in God’s eyes even before it becomes legal in the country. The ceremony is for man, not Him. He is, after all, omnipresent. He does not dwell in what we call God's house. He resides in the believer so if they say their vows in front of a group of believers they have had a church wedding for they are the Church. It is not a sacrament that must be performed by a pastor in a church.
Indeed, it is so much a tradition that at a marriage of a prostitute to a pimp the lady wore white. Yes, this happened. Not exactly following the symbolism. Many other people who have no church background will go through the marriage guidance classes though not really interested in the information just so they can have a church wedding. They never plan on ever being in church again, unless they divorce and remarry, but they followed the tradition. At least with funerals you will not have to do it again for that person in three to five years.