There is a sense, of course, in which tolerance is a virtue. If, by it, you mean tolerance on the part of the state, the forbearance of majorities toward minorities, the resolute rejection of any measures of physical compulsion in propagating either what is true or what is false then, of course, the Christian ought to favor tolerance with all his might and main and ought to lament the widespread growth of intolerance in America today. Or, if you mean, by “tolerance,” forbearance toward personal attacks on yourself or courtesy and patience and fairness in dealing with all errors, of whatever kind then, again, tolerance is a virtue. But, to pray for tolerance apart from such qualifications, in particular to pray for tolerance without careful definition of that of which you are to be tolerant, is just to pray for the breakdown of the Christian religion, for the Christian religion is intolerant to the core.
There lies the whole offense of the cross – and also the whole power of it. Always, the gospel would have been received with favor by the world if it had been presented merely as one way of salvation. The offense came because it was presented as the only way and because it made relentless war upon all other ways. God save us, then, from this “tolerance” of which we hear so much. God deliver us from the sin of making common cause with those who deny or ignore the blessed gospel of Jesus Christ. God save us from the deadly guilt of consenting to the presence, as our representatives in the church, of those who lead Christ’s little ones astray. God make us – whatever else we are – just faithful messengers who present, without fear or favor, not our word, but the Word of God. – J. Gresham Machen (1881-1937), from The Good Fight of Faith