We should not be held back by the thought that if they are not elect, they will not believe us, and our efforts to convert them will fail. That is true; but it is none of our business, and should make no difference to our action. In the first place, it is always wrong to abstain from doing good for fear that it might not be appreciated. In the second place, the non-elect in this world are faceless men as far as we are concerned. We know that they exist, but we do not and cannot know who they are, and it is as futile as it is impious for us to try to guess. The identity of the reprobate is one of God’s ‘secret things’ into which His people may not pry. In the third place, our callling as Christians is not to love God’s elect, and them only, but to love our neighbor, irrespective of whether he is elect or not.
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And then Packer reminds us of what salvation does for us, and how desperately all people need it.
There’s 100 pages more, but that there is the seed which Packer grows into a mature doctrine of evangelism. He’s a Reformed theologian, yes, so now and then he assumes something in Reformed theology that might conflict with Catholicism, but look at the final product, the finished work. I haven’t found anything objectionable in his final product