William Burkitt on Matthew 5:46

Yet farther to encourage us to this duty of loving our enemies, Christ assures his disciples, that he expects more from them than others; more than common humanity and civil courtesy towards friends; for even heathens by the light of nature were taught to love those that loved them: but he expected that Christianity should teach them better, and lead them farther, even to love their enemies, and to bless them that curse them.

Note, Love for love is justice; love for no love is favour and kindness; but love for hatred and enmity is divine goodness; a Christ-like temper, which will render us illustrious on earth, and glorious in heaven.

But Lord! how do men confine their love to little sects and parties? and from thence comes that bitterness of spirit of one party towards another; and oh! how hard it is to find a Christian of a true catholic love and temper.