en_tn/jhn/17/18.md

into the world

Here into "the world" is a metonym that means to the people who live in the world. AT: "to the people of the world" (See: rc://en/ta/man/translate/figs-metonymy)

so that they themselves may also be set apart in truth

You can translate this in an active form. AT: "so that they may also set apart themselves truly to you" (See: rc://en/ta/man/translate/figs-activepassive)