Compassion for suffering souls should unite believers with Christ, whereas harshness discourages the tempted.

Original passage

How little do we enter into sympathy with Christ on that which should be the strongest bond of union between us and Him—compassion for depraved, guilty, suffering souls, dead in trespasses and sins! The inhumanity of man toward man is our greatest sin. Many think that they are representing the justice of God while they wholly fail of representing His tenderness and His great love. Often the ones whom they meet with sternness and severity are under the stress of temptation. Satan is wrestling with these souls, and harsh, unsympathetic words discourage them and cause them to fall a prey to the tempter's power.