William Barclay illustrates what it means to be perfect as God is perfect, “Suppose in my house there is a loose screw, and I want to tighten and adjust this screw. I go out and I buy a screwdriver. I find that the screwdriver exactly fits the grip of my hand; it is neither too large nor too small, too rough nor too smooth. I lay the screwdriver on the slot of the screw, and I find that it exactly fits. I then turn the screw and the screw is fixed. In the Greek sense, and especially in the New Testament sense, that screwdriver is teleios, because it exactly fulfilled the purpose for which I desired and bought it” (William Barclay, The Gospel of Matthew, 3rd ed., The New Daily Study Bible [Edinburgh: Saint Andrew Press, 2001] 204–5, Logos).