Actually ,, ,It's obvious that a great differences between atheist and believe when they decide to marry, the great emotions gathered them not regarding to differences in belief between them ,,So in this case, ,wife should not speak about God to her husband , ,wife should pray and pray and pray, ,, wife should live the life which God preferred for her, wife should believe that it's not her responsibility that her husband is atheist ,,, finally wife should wait, and wait ant wait. Pray a lot and get closer to God by praying for the guidance of your husband. ..