In Guru Geetha of Skanda Purana, Lord Shiva told mother Parvathi that the ways to serve Guru is very secret and even gods don't know how to serve guru.
Why is it secret? What are the known ways to serve Guru? If we are living distant to our Guru, does service to the equivalent person (as it is said guru takes different forms to uplift humans) counted as service to our Guru? Can you quote few differences between service by disciple & by devotee?
The question may be broad but am just trying to understand the Guru principle.
Answer to my understanding
There are many ways to render service to Guru. But for everything, His grace and permission are required!
Few points from Guru Geetha of Skanda Purana (request community to correct grammatic mistakes, if any in following slokas):
Devakinnera gandharva pitaro yakshu charana muneniva janate guru srusrushana vidhim (Gods, forefathers, monks.. no one knows how to serve guru )
Though He doesn’t need anything, for self upliftment, disciple may offer service which pleases Him like keeping His ashram, temple clean. One has to know what Guru requires for Himself and for worship or for others and can provide them timely. One should not take his own decisions; he has to consult Guru while doing service.
Aaasanam sayanam vastram vaahanam bhushanaadikam sadakena prada dravyam gurosantoshakaram (chairs, beds, clothes, vehicles, ornaments may be offered by follower to please Guru !)
Even if you like distant from Guru, you can do paduka puja (worshiping Guru’s footware), following Guru shown path is real service to Him! One can respect, do service, any other spiritually enhanced person (follow his words until it does not violate Guru shown path) but should not take him as Guru! If Guru goes permanently to a distant place like Himalayas or if He leaves His body or if He Himself orders to follow another person as his Guru, then one shall follow that order.
Disciple does services, follows His words without doubt or confusion, without seeing personal benefit where as devotee does service only to gain blessings for materialistic things, for power, wealth or health.