1. They have reached a milestone anniversary and want to celebrate with family and friends by renewing their wedding vows.
2. They did not have the money for an elegant wedding all those years ago, but now want to elaborate celebration.
3. Perhaps they eloped the first time and want to have their families witness their vows now.
4. They have recently overcome a major crisis that has tested their marriage and now want to make a new beginning.
5. They want to reaffirm their vows because they love each other more with everyday.