1) Marriage was designed by God to portray the covenant relationship between Christ and his church. It displays God's covenant keeping love through the death of Christ for his bride, the church.
2) Staying married is about keeping one's covenant commitments, not just staying in love. Breaking the marriage covenant misrepresents Christ's unbreakable covenant with his church.
3) Both husbands and wives have distinct roles rooted in Christ's relationship with the church. A husband's role is to lead, protect, and provide for his family in a Christ-like manner. A wife's role is to willingly submit to her husband's leadership and help carry it through according to her gifts.