LOL, I still don’t get your point, do you want some particular church to define marriage and do away with the voters definition?
Is it your church that you want to define it for everyone?
That the State can better define Marriage, (which has existed as a church sacrament for thousands of years), or that the State can do better, even though no government in existence has survived more than a small fraction of that?
Christian views on marriage have not changed for two thousand years, but secular views have changed drastically.
Which is the more enduring definition?
You already wish to establish a definition of marriage which excludes the definitions of Islam and some other religions.
I have no real problem with that, but let's be honest about where that definition comes from.
If you leave that entirely to the State or the whim of the voters, you will have no greater stability in marriage definitions than you have in the state. Considering the changes of the State in the past few decades, the state is a borderline nutcase, but within the traditional Christian denominations, there has been no significant change in the definition of marriage.
(No 'church' which acknowledges homosexual unions nor polygamy has remained within the traditional Christian envelope).