Have you ever started a garden? It requires much work. For a seed to sprout, and grow into a healthy plant requires one to plant the seeds, water it, remove the weeds, and fertilize. The following is an analogy between the development of a plant to the development of a joyous life in man.
For a man to have a joyous future, requires one to plant the seed of happiness. What is this seed? This seed is any effort that helps others. One must have a pure mind like water, and guard against the weeds (greed, arrogance, and self love) which may take over the mind. We must also put sincerity (fertilizer) in. This sincerity comes from knowing that all mankind was created to live a joyous life.
If we continue to plant the seeds of good deeds with all these ingredients combined, the joyous life without suffering will be one day sooner: but if we share these seeds and ingredients with others, the joyous world will become one day sooner.