We are not called to be perfect.

What did Jesus say? Matthew 5:48 KJV
Be ye therefore perfect, even as your Father which is in heaven is perfect.

The entire point of Christianity is the perfection of a man or woman before and with God.

It is finished means we don’t have to do anything.

What does the Bible say?

James 1:22 KJV But be ye doers of the word, and not hearers only, deceiving your own selves.

1 Corinthians 9:24 KJV Know ye not that they which run in a race run all, but one receiveth the prize? So run, that ye may obtain.

Jesus work of salvation and sacrifice was finished on the cross, but as we live our work continues.