Be perfect

Jesus told those listening to Him in Matthew 4:48 to be perfect.  Is that even possible?  Not under our own power.  But the real meaning is to be complete and mature.  In James 1:4 says:

Let perseverance finish its work so that you may be mature and complete, not lacking anything.

So maybe in order to be mature, complete or perfect, we have to go through trials, difficult people, toxic environments, etc.