Your job is to display the finest example of Christian love possible. If your 'in-laws' accept it, fine! if the refuse it, the loss is theirs. In that respect, you are like the watchman on the wall. Your job is to provide the warning. Theirs is to hear the warning and take action. If they do not, they die in their sins but you will have saved yourself. If you do not provide the warning, they still die in their sins but their deaths are held against you.
Hungary's Orban: Refugees threaten Europe's Christian roots (Reuters)