Real love means service devoted to the welfare of another person, even if the person is inimical towards us. That is the test of love.
When we are physically strong, we engage in service. So that when we are not able to work, we will be able to remember Krishna, Prabhupada, our spiritual master and even our spiritual name in sub-consciousness.
Spending fifty percent for the service of the Lord or for propagation of spiritual knowledge in society by way of the sankirtana-yajna is the maximum display of human mercy.
Purport on Srimad Bhagavatam 1.17.42
To the degree our service is free from motivation – to that degree, our service will generate love (for Krishna).
Service is a privilege which is extended to a conditioned soul by the mercy of guru.
Seva is your only passage to the spiritual world.