Diwan refers to an act of worship. For Sikhs, worship takes many forms, including:
Sikhs believe in Waheguru’s omnipresence and a hold deep respect and admiration for him. They also place special importance on the gurdwara and places of pilgrimage, such as the Harmandir Sahib, the Golden Temple in Amritsar.
Worship and adore Him, and you shall be at peace forever.Guru Granth Sahib 896
Nam Japna which means repeating and constantly remembering the name of God, is one of the three foundations of Sikhism. The other two foundations are Kirat Karna and Vand Chhakna. Nam Japna can be performed either silently (by repeating ‘Waheguru’ in the head) or aloud. Sikhs believe that it is important to keep Waheguru in their mind at all times, as this will help them to become less selfish.
Repeating the Naam, the Name of the Lord, the mortal is exalted and glorified. Repeating the Naam, sin is banished from the body. Repeating the Naam, all festivals are celebrated. Repeating the Naam, one is cleansed at the sixty-eight sacred shrines.(Guru Granth Sahib 1142)