Following are a number of back-translations of Matthew 5:48:

• Uma: “We (incl.) must have good behavior with no faults [lit., no scales-scales], like the behavior of God our (incl.) Father who is in heaven.” (Source: Uma Back Translation)
• Yakan: “Therefore you shall be good like your Father in heaven is good.'” (Source: Yakan Back Translation)
• Western Bukidnon Manobo: “It is necessary that your treating everybody well is drawn tight, because our Father in heaven, His treating mankind well is drawn very tight.” (Source: Western Bukidnon Manobo Back Translation)
• Kankanaey: “Therefore it is necessary that you have no faults/lacks, like our Father in heaven who has no faults/lacks.'” (Source: Kankanaey Back Translation)
• Tagbanwa: “Therefore it’s necessary that you be like your Father who is in heaven, the quality of whose actions having no lack.'” (Source: Tagbanwa Back Translation)
• Tenango Otomi: “Your Father who is in heaven supremely does good in what he does. Be like that then, want that you supremely do good in what you do.” (Source: Tenango Otomi Back Translation)
• Enga: “Your Father who stands on top of the sky lives in such a way that he does not neglect any of the straight ways, but rather he holds to them; therefore live in such a way that you are doing the same.” (Source: Adam Boyd; click here for an explanation of this translation.)

  The idea is that God is complete in the sense that he does not neglect any good thing that he should do. He is complete in doing all that he should do. Therefore, we should behave in the same way, not neglecting to do all that we should do. It doesn’t mean that we are commanded never to make a mistake, but it does mean that we commanded not to be incomplete in how we carry out the commandments of God. To be sure, God does not make any mistakes, but the heart of Jesus’s command is for us to strive to be complete in our love.