In the Sermon on the Mount Jesus admonished the hearers to be perfect as the Father is perfect. It is a seemingly awesome commandment. What does perfection even mean? We probably think of sinlessness, but The Greek word which translates "perfect" means complete, consummated, or mature.
It is revealing to see this commandment in its broader context. Looking at Matthew 5: 43-48 we read the following:
Ye have heard that it hath been said , Thou shalt love thy neighbour, and hate thine enemy. But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you; That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust. For if ye love them which love you, what reward have ye ? do not even the publicans the same? And if ye salute your brethren only, what do ye more than others? do not even the publicans so? Be ye therefore perfect, even as your Father which is in heaven is perfect.
When seen within the flow of Jesus' overall thoughts, we note that the perfection of the Father is reflected in how we deal with enemies and those who mistreat us. Perfection like that of the Father is achieved when we love our enemies and treat them well.
Such a view or definition of divine perfection is certainly at odds with much of current Christian theology, which insists on eternal torment as God's final act toward many people. The Sermon on the Mount is recognized even by skeptics as perhaps the most profound and powerful ethical treatise ever written, but it is a clear indictment of Christian Orthodoxy at ever turn. Little in church doctrine and practice draws any support from these words of Jesus or reflects the perfecting that Jesus enjoined.