How do you pick a religion?

This question is not for those who are satisfied with picking a religion for circumstantial reasons (e.g. you were raised as a Muslim, the Methodist pastor is a nice guy, the Baptist church is the closest to my house, my friends are Mormon, my fiancee insists that I convert to Catholicism, Buddhism is trendy, I want to express solidarity with the persecuted Zoroastrians living in the highlands of Bogswoggle Province, etc.)

Let’s say you are picking a religion because you find the theology generally appealing, but you don’t agree with the need to observe the symbolic rituals involved. Regardless of whether you would end up observing the rituals, you clearly don’t accept the entirety of that religion’s dogma. If so, shouldn’t you simply assimilate the philosophy that you agree with and leave it at that?

If you accept a religion because it helps you feel spiritual or be a good person, shouldn’t you only follow the religion insofar as it helps you reach those objectives? Symbolic rituals may or may not help you feel more spiritual.

You can only accept the entire theology and dogma of a religion if you believe it is all true. To decide if a religion is true, you would need to have a good rationale to support the notion that that particular theology is entirely true.

Basically, my question is this: What is your rationale for believing your religion in particular represents the truth?