As you are likely to be engaged in controversy, and your love of truth is joined with a natural warmth of temper, my friendship makes me solicitous on your behalf. You are of the strongest side; for truth is great, and must prevail; so that a person of abilities inferior to yours might take the field with a confidence of victory. I am not therefore anxious for the event of the battle; but I would have you more than a conqueror, and to triumph, not only over your adversary, but over yourself. If you cannot be vanquished, you may be wounded. To preserve you from such wounds as might give you cause of weeping over your conquests, I would present you with some considerations, which, if duly attended to, will do you the service of a great coat of mail; such armor, that you need not complain, as David did of Saul’s, that it will be more cumbersome than useful; for you will easily perceive it is taken from that great magazine provided for the Christian soldier, the Word of God. I take it for granted that you will not expect any apology for my freedom, and therefore I shall not offer one. For method’s sake, I may reduce my advice to three heads, respecting your opponent, the public, and yourself.
So begins John Newton’s advice to a young controversialist, worth reading for anyone who feels obliged to contend for the truth in a public forum.