I cannot help feeling that the final explanation of the state of the Church today is a defective sense of sin and a defective doctrine of sin. Coupled with that, of course, is a failure to understand the true nature of Christian joy… There is not the real, deep conviction of sin as was once the case; and on the other hand there is this superficial conception of joy and happiness which is very different indeed from that which we find in the New Testament. Thus the defective doctrine of sin and the shallow idea of joy, working together, of necessity produce a superficial kind of person and a very inadequate kind of Christian life.
…So many people spend all their lives trying to find this Christian joy… I suggest that in ninety-nine cases out of a hundred this is the explanation. They have failed to see that they must be convicted of sin before they can ever experience joy. They do not like the doctrine of sin. They dislike it intensely and they object to its being preached. They want joy apart from the conviction of sin. But that is impossible; it can never be obtained. Those who are going to be converted and who wish to be truly happy and blessed are those who first of all mourn. Conviction is the essential preliminary to true conversion.
– D. Martyn Lloyd-Jones, Studies in the Sermon on the Mount