Is faith to be understood simply as a mental exercise, or is it somehow something more? [...]
When speaking of faith, we are describing a relational trust that is rooted in our participation in the life of God. St. Paul says that “faith works by love” (Gal. 5:6). Marriage, at its best and highest moments, can have something of this experience on a human level. The relationship is more than mental and emotional. It is physical and involves a union with the other than can only proceed from trust, freedom and love. It would not be wrong to describe such a relationship as faith. The Church asks husbands and wives to be faithful – which means far more than simply avoiding sex with other persons. It is little wonder that marriage is a common image used for the relationship between God and His Church.