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. That ye may be the children of your Father - Instead of ὑιοι children, some MSS., the latter Persic version, and several of the primitive fathers, read ὃμοιοι, that ye may be like to, or resemble, your Father who is in heaven. This is certainly our Lord's meaning. As a man's child is called his, because a partaker of his own nature, so a holy person is said to be a child of God, because he is a partaker of the Divine nature.
He maketh his sun to rise on the evil - "There is nothing greater than to imitate God in doing good to our enemies. All the creatures of God pronounce the sentence of condemnation on the revengeful: and this sentence is written by the rays of the sun, and with the drops of rain, and indeed by all the natural good things, the use of which God freely gives to his enemies." If God had not loved us while we were his enemies, we could never have become his children: and we shall cease to be such, as soon as we cease to imitate him.