It is amazing how this can happen even among believers. You think of something like slavery years ago. Consider the hymnwriter, John Newton. We think so highly of him and his experimental and searching hymns, and of his whole ministry here in London, and previously at Olney, and rightly so. But he was a slave trader as a youngster. He became a slave to slaves. He was converted on the ship bringing him back to Britain which was wrecked off the Irish coast, and he found the Lord. But for some years after that, he continued, believe it or not, with involvement in the slave trade, even after he was a Christian. He writes very frankly after some years, ‘It never occurred to me. I never thought about it. It never struck me, that there was anything disorderly or wrong’, and then he tells us how someone got hold of him, and really went for him. There were many believers who understood much more quickly. What a different case it was for someone like William Carey, who years before, even as a lad, as soon as he was converted gave up sugar because it was produced through the profits of the slave trade. So there were many who could see the issues are very clear. But John Newton couldn't see it. Nevertheless, once somebody really reproved him about it, he saw it very clearly, and he was so utterly ashamed of himself. ‘How could I not see this?’, he exclaims, ‘I who have seen the suffering first-hand? How was I so lacking in compassion, in human feeling, that even after conversion it never occurred to me that this was evil?’ He became one of the principal campaigners for the abolition of slavery, and he suffered considerably on account of his campaigning. When you look back at these things, you see it could even happen that even a Christian didn't feel badly about some terrible thing.
It can happen to all of us. You can work with somebody in the office, who is unsaved, and not feel any sympathy or any compassion or guilt at your failure to pray for them and witness to them, if opportunity arises. The subtlety of hardness of heart!