C. S. Lewis, writing to Don Giovanni Calabria, 20 September 1947, on how God uses hardships and even enemies to bring about the unity of the Church :
Common perils, common burdens, an almost universal hatred and contempt for the Flock of Christ can, by God’s Grace, contribute much to the healing of our divisions. For those who suffer the same things from the same people for the same Person can scarcely not love each other.
Indeed I could well believe that it is God’s intention, since we have refused milder remedies, to compel us into unity, by persecution even and hardship. Satan is without doubt nothing else than a hammer in the hand of a benevolent and severe God. For all, either willingly or unwillingly, do the will of God: Judas and Satan as tools or instruments, John and Peter as sons.
Even now we see more charity, or certainly less hatred, between separated Christians than there was a century ago. The chief cause of this (under God) seems to me to be the swelling pride and barbarity of the unbelievers. Hitler, unknowingly and unwillingly, greatly benefited the Church! — The Latin Letters of C. S. Lewis, 35, 37.