A pure devotee has no demand from the Lord. His only concern is to serve the Lord sincerely and seriously and he is not at all concerned about what will happen in the future. — Srimad Bhagavatam, 04.09.29.
Material sense gratification, sinful activity kills the propensity to serve Krishna.
As soon as we get to know the Absolute Truth, we should become fixed in it. Instead of wasting a single moment of time left, we should be engaged in serving Sri Hari.
Hammer every thought in your mind thinking of how to serve Krishna.
The Lord can be served by any ingredient, even the most common commodity — a flower, a leaf, a fruit or a little water, which are available in any part of the universe and without cost and thus the Lord is served universally by the universal entities.
Srimad Bhagavatam 2.9.36,
Giving wealth in service of the Lord, your profits will always increase. Thus you save yourself from repeated birth and death.