When we say that God is Love, do we teach men that their fear of Him is groundless? No. As much as they fear will come upon them, possibly far more . . . The wrath will consume what they call themselves; so that the selves God made shall appear. — George MacDonald 
My understanding of this is not that God seeks to harm us, but that God seeks to make us holy. Insofar was we are fond of our vices and impurities we have reason to fear God. This is because the fire of God’s love will burn away our imperfections and refine us into the people God created us to be.
 George MacDonald, as quoted in C. S. Lewis, George MacDonald: an Anthology (London: Geoffrey Bles: The Centenary Press, 1946), Kindle.
There seems to be some disagreement about whether it’s “MacDonald” or “Macdonald.” I’ve gone with the version that I think will elicit fewer corrections.