If you don't ponder the imponderables, how do you know that what you claim to believe is true?
One might say that including the Four Imponderables as part of one's faith is sort of like the rule in monotheistic religions that God is supreme.
-What did the Buddha and the Arahants really know?
-What can meditation ultimately achieve, really?
-Where did we come from and what's our purpose?
-What is the true nature of the world?
...how can you really know... anything?
We could assume a worst-case scenario (I don't believe this, btw, but it's to demonstrate a point): The Buddha and Arahants were just good philosophers and meditation can't achieve much more than psychiatric meds.
if this is true, without pondering it, how is Buddhism any different from all the other religions that want you to just take what they believe for granted?
The best things in life aren't things.