Give a copy of quran to someone. Each time one reads from it, you gain.
Donate a wheelchair to a hospital. Each time sick person uses it, you gain.
Participate in building a masjid.
Place watercooler in a public place.
Plant a tree. You gain whenever a person or animal sits in its shade or eats from it.
And the easiest of all, share this message with people. Even 1 applies any of the above, you gain.
Sebenarnya ada banyak lagi cara lain. This is just some part of it =) Semoga kita sama-sama mendapat kebaikan daripada ilmu yang disampaikan ini.