It should not be illegal in any state for same sex couples to partake in marriage. It is a human right to express your love for another person. This would allow for all same sex couples to wed no matter where they live, the marriages would be recognized by state and federal governments.
If enacted, no religious organization is being forced to marry a same sex couple and all churches and religions will have their own right to deny marriage service to a couple based on religious beliefs. Same sex couples will be able to wed at court houses, or by any ordained person who is willing to do so. There will be no pressure for anyone to participate in a same sex marriage, this is simply a human right that should be afforded to all humans be they straight, gay, or anything in between.