Human beings have been given two key abilities - rational minds, and spiritual freedom. If we develop our rationality, we can use our freedom well. So... it's important for us to understand spiritual truths, like the ones linked here.
People and God through time
It would be awfully nice to "know" that you're saved. A lot of Christians believe that you're saved if you accept Jesus Christ as your personal savior -- and in a sense that's true. If you REALLY accept Jesus Christ, and you live the way he told us to - shunning evils, loving the Lord, and loving the neighbor - then you're opening yourself to receive his love.