God is the God of covenants and a Promise Keeper. If we pray to God and expects Him to answer our prayers in line with the promises He made to us in His word then, we also ought to be faithful to our spouses and keep our wedding vows.
“For the LORD, the God of Israel, saith that he hateth putting away…” – Malachi 2: 16a
“Wherefore they are no more twain, but one flesh. What therefore God hath joined together, let not man put asunder.” – Matthew 19: 6