When i ask a Christian why do you believe in…

When i ask a Christian why do you believe in Christianity
Why not other religions?!is there something special or does the bible contain scientific verse which is now discovered !? How do you know that this is the word of god ?! simply his Answer will be
Because Jesus said i am the only way to God And he died for our sins .
What i observe from this is that they look like if they are really programmed or like Christianity is really weak and the Christians are follow their emotions.