en_tn_condensed/act/01/21.md

General Information:

Here the word "us" refers to the apostles and does not include the audience to whom Peter is speaking. (See: rc://en/ta/man/translate/figs-exclusive)

Connecting Statement:

Peter finishes his speech to the believers that he began in Acts 1:16.

It is necessary, therefore

Based on the scriptures that he quoted and on what Judas had done, Peter tells the group what they must do.

the Lord Jesus went in and out among us

Going in and out among a group of people is a metaphor for openly being part of that group. Alternate translation: "the Lord Jesus lived among us" (See: rc://en/ta/man/translate/figs-idiom)