All right. I'll bite, but we actually have had a lengthy debate on this subject already.
Even though this thread is about Canadian policy, here in the US we have a general tenant called Separation of Church and State. Marriage may be a contract with God in your eyes, but in this case they aren't asking for the Church's permission to marry. This is dealing with the legal contract of marriage. I'm pagan so I don't believe in your God. Does this mean that legally my marriage is null and void? Would that make all Muslim, Hindu, Buddhist marriages null and void? There are legal ramifications to marriage far beyond the narrow minded Christian view, i.e. taxes, insurance, beneficiaries, will and death issues, divorce, etc. This issue, no matter how much Christians want to make it so, is not about moral values. That is for you and you alone to decide, it is not for you to impose on others. This is about legal equality, and personally I think it's about time that they are treated equally
under the law. (Note, I did not say give them special rights, having the same rights as those who are heterosexual, regardless of religious beliefs, is not special rights.)