Is Jesus omnipresent?

Matthew 18:20 NWT

For where there are two or three gathered together in my name, there I am in their midst.

Who is speaking here?
How can Jesus be with all believers who are gathered together in his name?
Matthew 28:20 NWT

But when there is Teaching them to observe all the things I have commanded you. And look! I am with you all the days until the conclusion of the system of things.

How can Jesus be with his believers all the days?