"We are myriad beings, prone to errors in judgement, miscalculations, and mistakes."....."Mat 5:48 YOU must accordingly be perfect, as YOUR heavenly Father is perfect."
In this life everyone deals with imperfection based on experience some more successful than others. The best reference of perfection is the Father in heaven.
Which Father can only be understood and perceived by individuals. Thus, I would agree with the apostle Paul when he said "You have no need of a teacher."