so that you may be confirmed in what is better, in order that you may be sincere and without offense on the day of Christ
Other versions
King James Version
That ye may approve things that are excellent; that ye may be sincere and without offence till the day of Christ; English Standard Version
so that you may approve what is excellent, and so be pure and blameless for the day of Christ,New International Version
so that you may be able to discern what is best and may be pure and blameless until the day of Christ,