I come with glad tidings of a world made free.

(A script from the Avengers)

A : We have no quarrel with your people.

B: An ant has no quarrel with a boot.

A: Are you planning to step on us?

B: I come with glad tidings of a world made free.

A: Free from what?

B: Freedom. Freedom is life's great lie.

Hello, great people there. This is a script of the Avengers I am learning English with and I was wondering why there is "come" in the conversation. I think that considering the context, it should be "have come" or "came" or "have" is just omitted or is there a reason for the form?

Thank you so much as always and I really appreciate your time and help.