So, I don't agree all that much with any major (or even minor) political party. But political parties shape the world I live in, proportionally to their popularity. So I hold my nose and vote for the lesser of two evils in the hope of ameliorating the levels of evil in the country. I don't join any party, but I do tend to support the Democratic Party because I find their influence on things less damaging than Republican influence in the current political climate. (And supporting a minor party would accomplish even less, as far as I'm concerned, so I don't go shopping for a slightly less objectionable smaller party.)
On the other hand, if you accept the tenet that God created mankind and not the other way around, popularity of a religion has no influence on whether it's right. A majority religion doesn't get to define God for everyone the way a majority political party can define the government. So I have zero afterlife-based incentive to back any existing religion unless I find myself 100% in agreement with it. Way too many people act like a sect's popularity means they get to say what God wants from us...they may phrase it as confirmation that their interpretation of God's Will is correct, but really it's just, "We're popular, so God must prefer us."