I'm sick of being hit over the head with stuff like " If you are Christian and are going to argue in favor of traditional marriage, it doesn't help that so many in your camp are poor examples of what marriage is supposed to be -- a lifetime union, steadfast and binding through good times and bad, sickness and health.'
Our example is Christ, not other people and their problems. None of us is perfect, EVERY marriage has its challenges, and sometimes, things don't work out as hoped. That is simply life in a fallen world. It doesn't further help marriage to demean those who fail at it.
If the Church has failed in this part of her mission, it's because it has permitted secular teaching on marriage to creep in.