But surly this underpins your life as a Muslim? If these things are not true, then maybe others are not true. Maybe Allah does not exist, how would you know?

If you just assume it is true, then it is a totally arbitrary decision, probably instilled through the culture in which you were brought up.

We are very lucky in the 21st century; there are good methods of finding what is true and what is not.

The truth of the reasons I live my life like I do mean a lot to me, I would never base a decision of truth on an arbitrary choice where it affects me and those around me.

The truth of these things matters a great deal.

Regards