By Elder Paisios the Athonite
The best of all memorials we can do for the deceased is to live careful lives, and undertake the struggle to do away with our shortcomings in order to brighten our souls. This is because our freedom from material things and the passions of the soul, besides bringing us relief, it brings also comfort to our departed ancestors of all our generations. The departed feel joy when one of their offspring is near to God. If we are not in good spiritual condition, then our parents, our grandparents, and our great-grandparents of all generations suffer. "See what offspring we have made!" say the sad ones. If we are in good spiritual condition, however, they rejoice, because they helped us to be born and God somehow is obligated to help them.
Therefore, that which will give joy to the deceased is for us to strive for us to please God with our lives, that we may meet with them in Paradise and live together in eternal life. Hence, it is worthwhile to beat upon our old self to become new, to neither harm ourselves or other people, but to help ourselves and others, either living or fallen asleep.
Source: Translated by John Sanidopoulos.