Simply see that you are at the center of the universe, and accept all things and beings as parts of your infinite body. When you perceive that an act done to another is done to yourself, you have understood the great truth.
Some help others in order to receive blessings and admiration. This is simply meaningless. Some cultivate themselves in part to serve others, in part to serve their own pride. They will understand, at best, half of the truth. But those who improve themselves for the sake of the world -- to these, the whole truth of the universe will be revealed.
The fourth (of the four cardinal virtues) is supportiveness: this manifests as service to others without expectation of reward. (Paraphrased: Such service is not a mere conforming to some external rule of behavior, but instead a manifestation of your original nature).
To practice virtue is to selflessly offer assistance to others, giving without limitation one's time, abilities, and possessions in service, whenever and wherever needed, without prejudice concerning the identity of those in need.