يَدْعُونَنَا رَغَبًا وَرَهَبًا (and call Us with hope and fear - 21:90). This may be interpreted to mean that they call Allah Ta` ala both in comfort and distress. The other explanation of the verse is that during their prayers they remain suspended between hope and fear hoping that Allah would forgive their sins and fearing that their lapses may bring on them His displeasure.