Influence

The act of writing something down reinforces it in humans. If you write something down and show it to people it will influence you even more.

This means that apologetics discussions do not, by and large, work. The very act of writing down the same arguments so frequently serves to solidify both sides. Apologetics does not convince unbelievers - it solidifies already-existing believers (and also solidified unbelievers). The surest way to influence yourself to stick with whatever you believe is to argue for it.