I want to respond with a series of truths and finally resources for all to peruse.
Spiritually, this is not about marriage, it is about confusing believers and non-believers on God's word.
People will begin to do what seems right in their own eyes.
It is difficult as a believer to confront and correct our brothers and sisters in love. But biblically Christians are called to do so.
God does not say sit by and watch others fall in sin and love them as they fall.
What would Jesus do? Well He will turn away those who wish to persecute you when they have sins too. But even as He gave the woman at the well the opportunity at life abundantly, He called out her lifestyle with men. She reported to others to "come see a man that knows all about me."
Personally, I try to love everyone like Jesus does. I will stand on what I believe, and protect what I believe. I will not condemn others for believing or behaving contrary to what the Bible says. I will obey the will of God and do what He says to say and do, in love.
Correction in Love is of God, and is permitted. Judging is God's place.
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