J. N. Darby.
The cross of Christ is where everything is morally perfected. There the whole question of good and evil was solved. The world despises the cross; and God meant it to be a despicable thing - a gibbet. "But God hath chosen the foolish things of the world to confound the wise, that no flesh should glory in his presence." There, on the basest thing in the world, He has hung salvation. But the moment I am inside, I find everything in the cross - the uttermost sin of man in enmity against God, all the power of Satan, but the perfect man in Christ. "The prince of this world cometh, and hath nothing in me." But, on the other side, God is there in perfect righteousness against sin, and in perfect love for the sinner; and as you go on, you find that the new heavens and the new earth - all things in short - will be perfected by the cross. There I have perfect righteousness against sin, and perfect love towards the sinner; and I find peace and rest, not merely rest but God's rest. For He rests in His love, in the blessedness of those He has brought near in Christ, and He will bring them into His rest in glory. (From article: 'Christ and His Reconciliation.')
We are apt to make a mistake in speaking of our weakness and unprofitableness, forgetting that it is when we have done our duty, we are unprofitable servants. When we speak of it, we mean our failure; and so, when we speak of our weakness of spirituality or conduct we mean failure. But when Paul speaks of weakness, it is that which makes room for power ("when I am weak then am I strong"); and the result fully produced is with the consciousness of there being no strength in us. This is a very different thing from our failure. Our failure ought to lead us to humble ourselves before God for that which led to the failure. If we have not done what we ought, why have not we? We cannot glory in not having done it. There is a strength that the babe in Christ may have and needs - power guided by wisdom, and this does not fail. When we have not been emptied of self and are full of self-confidence, we must be broken down. Pretension to strength is always in the way for failure. The first step towards failure is forgetting our entire and absolute dependence. As Christians we know we have no strength, but we forget we have none. (From article: 'In Christ.')