From Buddhism: Parabhava Sutta

The four matters discussed in this sutra could briefly be stated thus:

(1) to supply the worldly beings with means of living, and to feed animals with pity;

(2) to support the poor and needy with compassion;

(3) to refrain from eating meat, and to remain firmly fixed to observing the five precepts;

(4) to respect the sramanas with due regards and honor.

In addition, the sutra mentions that the person who complies with the four matters summarized above, worships and honors the Buddha in all respects. In other words, although he does not worship the Buddha, his act of cleaving firmly to the ‘four matters’ is equivalent to worshipping the Buddha.