If you would be perfect, sell what you possess, and you will have treasure in heaven.
To be perfect, we might say, is impossible. Many business studies teachers and 'Gurus' will tell you that perfection is the enemy of success - well, in a world where 2% better than your opponents' 78% is the difference between success and failure, they are right.
But Jesus means it - we should aim for perfection.
Jesus is also the means of our salvation - his actions have made us perfect in the sight of God. So, unlike the businessman, or in the story of the young man in today's Gospel who went away feeling that he could never become perfect, perfection is possible for us and the thought that we can not be perfect, we must remove from our lives. Seek to be perfect, because then the Lord will perfect you. The Apostles taught us this - see Phillipians 3:12, James 1:4, Collisions 1:28 for examples.