The obvious answer here is "the one that you hate." Or, the Christian god of Abraham.

The preamble is not subtle: "Canada is founded upon principles that recognize the supremacy of God and the rule of law."

Now, legally/philosophically speaking, the Canadian concept of free-speech is laughably weak, as is all Canadian rights. Specifically, section one clearly states that rights are subject to "reasonable limits prescribed by law as can be demonstrably justified in a free and democratic society". Effectively, if the government decides that you're "not reasonable," you have no rights.

The American system is quite clear about their rights being absolute and derived from God, where the idea is that the government is to uphold the existing divine rights afforded to all human beings, as opposed to the British system of which Canada (and the rest of the common-wealth is based off of) is a part of, where the government _grants_ the rights.

Another example of this is the British crown, in which authority is given by God. Many of the older cities derive their local authority in the same way. If I recall correctly, I believe that the city of London is so old that they actually mixed it up, and derive theirs from "time immemorial."

> The American system is quite clear about their rights being absolute and derived from God

No, the legal system is not; there are non-legal documents which claim both of those things, but being subject to “reasonable limits prescribed by law as can be demonstrably justified in a free and democratic society” is very much how the US elgal system treats them. There is even, in federal Constitutional case law, an established, gradated system of tests (rational basis test, intermediate scrutiny, and strict scrutiny) depending on which right is at issue and for whom it is being limited as to whether there is sufficient justification.

Serious question: Why would I hate any god?