From there, examine how his or her family feels about welcoming someone of a different faith into their family - and if you plan on having children, then it's important to come to an agreement not only with your partner, but also with the in-laws, about how the child will be raised. Celebrating holidays can be a sticking point with families as well. Work out the details of how you will observe religious holidays before taking the plunge. Unfortunately, knowing when it won't work is as important as actually making it work. Experts say couples handle differences better when neither is too invested in his or her faith and values. However, it's best to know before making any important decisions about your future.