You are making massive assumptions about God.
All marriages between Christians are presumed to be valid unless it can be proved otherwise. It is for a tribunal to decide not the persons themselves as they are likely to be biased. Even tribunals can get it wrong but one thing is certain, God can't be fooled.
As I said I don't make the rules the Church does and I try to live by them. When I fail I don't sit back and presume God will take no notice, I start again. Presumption is a sin against the virtue of Hope.