Answer:
The effect of faith and religion on marriage would depend very much on which religion you practice. Some religions encourage multiple wives, while others teach the virtues of monogamy. Some religions believe that marriage should be forever, such as the sealing ceremonies performed by the Church of Jesus Christ of Latter Day Saints.
Each religion has it's own ideas on what exactly marriage means, and this meaning may change slightly from branch to branch of that religion. A married couple where one person practices a different religion to the other may bring hurdles which are difficult to overcome.