That if we have improved our character it is possible for us to get on with everybody.
We must then do our best to endeavour to amend our faults and correct our manners. And if we succeed in correcting them we shall certainly be at peace, I will not say with men, but even with beasts and the brute creation, according to what is said in the book of the blessed Job: “For the beasts of the field will be at peace with you;” for we shall not fear offenses coming from without, nor will any occasion of falling trouble us from outside, if the roots of such are not admitted and implanted within in our own selves: for “they have great peace who love your law, O God; and they have no occasion of falling.”
Source: Institutes (New Advent)