Ahh well if you do doubt just think about it.
Cause sometimes the devil feeds us thoughts that don't actually belong to us

Whenever I doubt that God is real I typically recall the life experiences that I went through, usually the times I could have died.

If that isnt enough then I start thinking about why there's so much design in us.
Why we are even able to form thoughts, there is so much in the human body that's organized in a way that definitely wasn't formed by an accident.

But usually people don't believe this cause God hasn't opened their eyes yet.

‭John 9:41 AMP‬
[41] Jesus said to them, “If you were blind [to spiritual things], you would have no sin [and would not be blamed for your unbelief]; but since you claim to have [spiritual] sight, [you have no excuse so] your sin and guilt remain.