John Piper said this quote
“ ...we should all fortify ourselves against the dark hours of depression by cultivating a deep distrust of the certainties of despair. Despair is relentless in the certainties of its pessimism. But we have seen again and again, from our own experience and others', that absolute statements of hopelessness that we make in the dark are notoriously unreliable. Our dark certainties are not sureties. ”