This is how love is made complete among us so that we will have confidence on the day of judgment: In this world we are like Jesus. (NIV)
In this [union and communion with Him] love is brought to completion and attains perfection with us, that we may have confidence for the day of judgment [with assurance and boldness to face Him], because as He is, so are we in this world. (AMP)
Herein is our love made perfect, that we may have boldness in the day of judgment: because as he is, so are we in this world. (KJV)