A comma or no comma before “and”??

[raytung31]

Dear Teacher.

For the sentences below, which one is correct? A comma or no comma before “and”??

We all like Ben because he is nice, friendly, helpful, and kind.
We all like Ben because he is nice, friendly, helpful and kind.

Please tell me why or why not?? Thank you.

[SoothingDave]

It's entirely optional as a matter of style, unless punctuation is required to resolve ambiguity. "Oxford comma" if you want to Google it.

[bhaisahab]

There are too many adjectives for your sentence to be natural. I agree with SoothingDave about the comma.