One should avoid bad deeds because it is ethically and morally wrong. In a religious perspective it is wrong, for example, to put on a blood transfusion. Based on the article (Accept or Refuse Blood Transfusion) states: Professor Gerhard von Rad has pointed out that Genesis 9:3, 4 “is not an isolated ‘dietary law’ at all . . . but an ordinance for all mankind.” (Genesis—A Commentary, 1961) Remember, too, that in Genesis 9:3-6 the prohibition on blood was linked with God’s statement about man’s having even higher regard for the life of other humans. Rabbi Benno Jacob observed:
“The two prohibitions belong together. . . . The permission to eat meat, but without its blood, and the prohibition against shedding human blood indicate the place of man within the world of the living . . . In summary: the reason for the prohibition of blood is of a moral character. . . . Later Judaism regarded this passage as establishing fundamental ethics for every human being.”
And, In society, it is wrong for a minor to be with a person who is older than themselves, steal, or cheat on a spouse. We avoid bad deeds in order to have a clean conscious, to oblige with society rules, to be ok with others, to not disobey the norms of a law, etc. In conclusion, there are many reason to avoid bad deeds. Be it personal, because of society or religious.