Since love and truth are the cornerstones of life and since they are but other names for praise and thanksgiving, it follows that praise and thanksgiving are important components of prayer. This is because prayer in its truest form is an alignment between the spiritual self of each of us with the spiritual Power that defies human understanding.
All the angels are amazed at humans, who through their holy works appear clothed with an incredibly beautiful garment. For the angel without the work of the flesh is simply praise; but the humans with their corporeal works are a glorification! Therefore the angels praise humans' work.