Remove the commas. By enclosing "who are not bad" in commas, you are making it a nonrestrictive appositive. That is to say, you are saying all people are not bad and should enjoy life.
Given your intended meaning, you need a restrictive appositive. The difference in meaning between the two is illustrated in The Chicago Manual of Style:
My cat Philby is fat. [I have two cats.]
My cat, Philby, is fat. [I have one cat.]
In the first example, the writer has more than one cat; of all her cats, Philby is the fat one. Fatness is restricted to Philby. If the writer left out the name "Philby" and wrote just "My cat is fat", it would not be clear which of her cats she is referring to. So here, the word "Philby" is a restrictive appositive, and is essential to the meaning of the sentence. As such, there should be no commas around it.
Conversely, in the second example, the writer has just one cat. So leaving out "Philby" would not make the sentence unclear. It would still be clear which cat the writer meant, as there is only one in question. Here, "Philby" simply adds incidental and non-essential information, i.e., it tells us the cat's name. Since it's inessential, it gets set off by commas from the rest of the sentence.
To sum up:
- Putting commas around an appositive makes the appositive nonrestrictive. They imply that the appositive encompasses the entire subject: in case of the Chicago example, Philby is the only cat; in your sentence as written, all people.
- Leaving off the commas makes the appositive restrictive. It limits the applicability to the specific entity mentioned in the appositive: in case of the Chicago example, Philby alone of all the cats; in your sentence if you leave off the commas, only the good people.
Grammar Girl also has a good explanation of commas in relation to restrictive and nonrestrictive appositives.