There are great secrets and mysteries behind tears which the physiologists cannot explain still. In ordinary cases tears are considered as the sole property of children. Tears come at times of happiness, gratitude, etc. which fall under the category of noble emotions as far as the human values are concerned. But from the religious point of view tears are more the property of the devotees, of course depending on the sincerity of their quest for the Lord. In spiritual life repentance and the devotion to God, especially that noblest type of devotion of the gopikas which made them reach right up to the portals of death due to separation from the Lord, are the causes of tears.
The tears of pure devotion come from the outer corners of the eyes and have no saltish taste. But tears of mere human emotions are saltish in taste and come from the other parts of the eyes Kirtans are the best means for the production of devotional tears. Sri Ramakrishna used to remark on the scarcity of even one drop of tear for God while gallons of tears are shed for worldly material wants. It is a most blessed experience to weep for the sake of God. Anandamayi Ma used to shed tears out of devotion during bhajans. It is believed that whenever and wherever the chantings and kirtans of Sri Rama are going on upon the earth, Hanuman, the humblest devotee of Him, used to be present with tears of devotion then and there.
Tears of repentance due to intense devotion to the Lord are the greatest purifiers of the heart and the most expedient means for installing the Lord therein. Through tears of pure devotion to the Lord one can even attain the state of jivanmukta.