It’s ok if one finds themselves from time to time or persistently not believing in nor accepting of a Higher Power or The Almighty, but blasphemy is the one line which shall never be crossed. Blasphemy includes condemning and belittling the religions of others.
Periodically, the religious faith and practices of any believing person, fluctuates. But, trust me, He’ll always be there waiting on your return to Him.
Perhaps you’ve had a different experience…?