Why do Organized Religions try to Teach What They are Not Sure of ?

Read your bible, people. It is the ultimate source for all things. Spiritual health, physical health, emotional health, peace, love, joy, it's all in there. If more people would read their bibles and live their lives according to it's guide lines, the world would be a lot better off. I'm not talking about what catholics believe or baptists or methodists, so on, teach, I'm talking about what the bible teaches, the holy word of God. Get with the program people.