Once [Carey] was talking with a Brahman in 1797. The Brahman was defending idol worship, and Carey cited Acts 14:16 and 17:30.
God formerly "suffered all nations to walk in their own ways," said Carey, "but now commandeth all men everywhere to repent."
"Indeed," said the native, "I think God ought to repent for not sending the gospel sooner to us."
Carey was not without an answer.
He said, "Suppose a kingdom had been long overrun by the enemies of its true king, and he though possessed of sufficient power to conquer them, should yet suffer them to prevail, and establish themselves as much as they could desire, would not the valour and wisdom of that king be far more conspicuous in exterminating them, than it would have been if he had opposed them at first, and prevented their entering the country? Thus by the diffusion of gospel light, the wisdom, power, and grace of God will be more conspicuous in overcoming such deep rooted idolatries, and in destroying all that darkness and vice which have so universally prevailed in this country, than they would have been if all had not been suffered to walk in their own ways for so many ages past."You must have a very big view of God and His purposes to even begin to wrap your mind around these thoughts. But these are Biblical thoughts that Carey is sharing with the Brahman. They are well-thought-out Biblical thoughts. They are not based in any, "...well I think..." or "...I just feel that..." type arguments. Piper closes this quote by saying the following:
Carey's answer to why God allowed nations to walk in their own ways is that in doing so the final victory of God will be all the more glorious. There is a divine wisdom in the timing of God's deliverances from darkness. We should humble ourselves to see it, rather than presume to know better how God should deal with a rebellious world.(This story of William Carey comes from Tom Wells book A Vision for Missions.)