In the Sermon on the Mount, when Jesus told us to be perfect as our heavenly Father is perfect,
he was emphasizing our need to rely completely on God.
No one can be perfect except by justification through Jesus Christ.

Certainly, because of our human limitations, we fall short of the morality God wants us to live.
Yet, if we continually repent and believe in the atoning work of Jesus Christ for us,
God counts us as righteous.

The Plain Truth