Listen carefully, Mr PM. You. Don't. Have. That. Right.
You were elected to handle federal laws and issues, not state laws, and if a state democratically passes a law that permits Australian citizens who presently lack the same rights under law as other Australians enjoy, you do not have the right to overturn that because you happen to think differently. That has a name: it's called tyranny.
Your objections are religious, and the Constitution of the Commonwealth of Australia - you may have heard of it - states that no federal laws may be passed that favour one religion (or many religions) over another, including those who do not subscribe to your religious moral code:
116. The Commonwealth shall not make any law for establishing any religion, or for imposing any religious observance, or for prohibiting the free exercise of any religion, and no religious test shall be required as a qualification for any office or public trust under the Commonwealth.
This would be imposing a religious observance. It's unconstitutional, immoral, politically outrageous and as it happens I think contrary to the ideals of the Labor movement, not that that carries much weight these days. Gay rights were introduced by Labor, and it seems Labor will take them out, just like Cosby said about fatherhood.
If you want a solution, one that doesn't break the constitution and which is consistent with our laws and principles, try this. I wrote it for Howard's government. It seems yours might do well to read it as well.