How community shapes ideology

It shouldn't be surprising that for a social primate relationships are more important in shaping ideology than reason or evidence. In Christianity it is impressed on the believers to meet and gather often. Koinonia in Greek -"Koinonia is a transliterated form of the Greek word, κοινωνία, which means communion, joint participation; the share which one has in anything, participation, a gift jointly contributed, a collection, a contribution, etc. It identifies the idealized state of fellowship and unity that should exist within the Christian church, the Body of Christ." (wikipedia)

In Islam there is a Hadith that states marriage is half of the Din. "When a man marries, he has fulfilled half of his religion."