…be perfect, just as your Father in heaven is perfect.Matthew 5:48
Our Lord’s exhortation to us in Matthew 5:38-48 is to be generous in our behavior toward everyone. Beware of living according to your natural affections in your spiritual life. Everyone has natural affections— some people we like and others we don’t like. Yet we must never let those likes and dislikes rule our Christian life. “If we walk in the light as He is in the light, we have fellowship with one another” (1 John 1:7), even those toward whom we have no affection.
The example our Lord gave us here is not that of a good person, or even of a good Christian, but of God Himself. “…be perfect, just as your Father in heaven is perfect.” In other words, simply show to the other person what God has shown to you. And God will give you plenty of real life opportunities to prove whether or not you are “perfect, just as your Father in heaven is perfect.” Being a disciple means deliberately identifying yourself with God’s interests in other people. Jesus says, “A new commandment I give to you, that you love one another; as I have loved you, that you also love one another. By this all will know that you are My disciples, if you have love for one another” (John 13:34-35).
The true expression of Christian character is not in good-doing, but in God-likeness. If the Spirit of God has transformed you within, you will exhibit divine characteristics in your life, not just good human characteristics. God’s life in us expresses itself as God’s life, not as human life trying to be godly. The secret of a Christian’s life is that the supernatural becomes natural in him as a result of the grace of God, and the experience of this becomes evident in the practical, everyday details of life, not in times of intimate fellowship with God. And when we come in contact with things that create confusion and a flurry of activity, we find to our own amazement that we have the power to stay wonderfully poised even in the center of it all. From My Utmost for His Highest Updated Edition