Because religion is laughable

Prayer Helmet

Funny Prayer Helmet Religious Picture - Only $249.55
Funny Prayer Helmet Religious Picture - Only $249.55
It enhances your prayers so God can hear them clearly!  God also thinks "you really mean it" this time.  Mega Church Inc.
The heavens are terribly silent.  Prayers return unanswered to the supplicant, leaving the poor soul to wrestle with several choices:

1. There is no god.
2. There is a god but she doesn't answer prayer.
3. The prayer was wrong.
4. The supplicant did not deserve an answer.
5. The answer was "no".
6. The answer was "not yet".
7. Time passes and the thing happens. The answer is "yes".

This leaves an immense amount of wriggle room for the non-existent god to exist in the faithful mind.