Therefore you shall be perfect, just as your Father in heaven is perfect. (WEB)
The Greek word for 'perfect' that Jesus uses in this text means 'complete' or 'mature'. We don't have to strive for this because in Christ we are already accepted in the beloved. The more we understand the fatherhood of God, the more we will realize that everything that He wants to give us is based on the fact that we are part of His family.
In Ephesians 3:14-15, Paul the Apostle prays...14 For this cause, I bow my knees to the Father of our Lord Jesus Christ, 15 from whom every family in heaven and on earth is named, (WEB). Jesus died to reconcile us to our Father (2 Corinthians 5:18-19) and restore to us all that is good and perfect from the Father of Lights (James 1:17).
May each and every one of us know that we are perfect and complete because our Father is perfect. This is a gift already given to us because we are in Christ and part of our everlasting inheritance. May the revelation of your completeness in Christ set your heart at rest.
I have been crucified with Christ, and it is no longer I that live, but Christ living in me. That life which I now live in the flesh, I live by faith in the Son of God, who loved me, and gave himself up for me. (WEB)