Dear Ms. L:

You wrote:
> I am the director of public information at College X.
> We are currently working on a new mission statement and I
> would like for you to look at it and make sure it is grammatically
> correct. Here is the most current version:
>
> “College X enriches the academic, technical and
> cultural life of our diverse communities. We are committed to offering
> traditional and alternative approaches to education, providing quality
> instruction, and promoting lifelong learning.”
>
> Thank you for your help.
> respectfully,
> L
>
It sounds fine. The only problem is that you are not consistent in the use of the comma. In the first series, there is no comma before the and (“technical and cultural”), while in the second series there is a comma (“instruction, and promoting”). More authorities prefer the less ambiguous way you did it in the second series. To be consistent, add a comma after “technical.”

See https://englishplus.com/grammar/00000070.htm or “Commas in a Series” in Grammar Slammer for more on this.