In this episode Dan Cox and Andy Harris discuss:
Matthew 5:48 (ESV):
"You therefore must be perfect, as your heavenly Father is perfect."
They discuss this with an emphasis on:
Hebrews 10:14: "For by a single offering he has perfected for all time those who are being sanctified."
Jesus calls us to perfection, knowing that we cannot acheive this by our own power, and this is the call of Jesus with any of His commandments...He knows that the only way to become perfect, or walk in the commands He gives, is by coming to Him, knowing Him, and allowing Him to empower us, through His Holy Spirit dwelling in us, to walk out what He's called us to.
Jesus gives impossible commands, because with Christ all things are possible...and without Him, it is unachievable...it literally cannot happen.
And this is the crux of this command...in order to become perfect, we must walk in His finished work, by His power, through relationship with Him...it's not by earning or striving for perfection, but by surrender and allowing His Spirit, to give us His Power in our weaknesses, so we can walk the path of sanctification. His power, our surrender.
This is a great episode, check it out and download the PDF worksheet that goes with it here