Guru-seva yoga is the yoga of selfless service rendered to the guru. It is an effective sadhana for purifying the heart. One who practises this yoga will overcome I-ness and mine-ness, and his mind will become alert and dynamic.
In serving the guru, one must follow all commands of the guru without grudging. The disciple who has faith in the guru argues not, thinks not, reasons not and cogitates not. He simply obeys, obeys and obeys. Sometimes the methods and ways to eradicate the disciples faults prescribed by the guru may not be to the disciples immediate liking, but he must have firm faith that it is for his own benefit. Far more than worship, garlanding and other outward manifestations of adoration, obedience to guru is greater.
There is indescribable joy and peace in the practice of guru-seva yoga. Guru bhakti and guru seva are like the two oars of the boat of sadhana that takes the disciple across the torrential stream of samsara.