[Grammar] Join us or Join with us?

[Vidura]

Join us or Join with us?
What is correct?
If you can, please give some examples as well.
Thank you.

 

[riquecohen]

Join us is preferable, as in "Will you join us for lunch?" or "Please join us in support of this policy."

I have heard join with us used in some contexts, as in "Join with us in prayer."