en_tn/phm/01/06.md

the sharing of your faith may be effective

Possible meanings are 1) "the way you tell others what you believe may cause them to believe also" or 2) "the way you believe the same way we do will cause good things to happen."

be effective, so you will have a full understanding of every good thing we have

"have a good result, and you will completely understand all the good things we have"

in Christ

"because of Christ" or "because we are Christ's people"