I personally think this is one of the biggest challenges a marriage will face. As a "married couple," we feel like we are united in this life together and go through life in the same direction and with the same experiences. However, it often turns out that while we are a "couple," we are also two individuals who are in a Christian journey and walk with our personal Lord and Savior. There are going to be times when one of us feels weaker in their walk or less secure in their understanding. This can make life a little harder.
I think the only answer that truly works in times like these is prayer and spending personal time with God. Praying for each other regularly and with intention is something we should be doing always, but especially during times of struggle, praying for your spouse is incredibly important. Fighting and resentment can start to build up during these times, and not having regular conversations with God can certainly add to the problems.
Marriage retreats, marriage counseling, or perhaps spending some time individually in women's or men's Bible studies can allow a spouse to address some of the individual issues a spouse might be facing. Encouraging one another during this time is also very important; instead of making each other feel "less than," encouraging one another will do wonders.