A zealous man in religion is pre-eminently a man of one thing. It is not enough to say that he is earnest, hearty, uncompromising, thorough-going, whole-hearted, fervent in spirit. He only sees one thing, he cares for one thing, he lives for one thing, he is swallowed up in one thing; and that one thing is to please God. Whether he lives, or whether he dies — whether he has health, or whether he has sickness — whether he is rich, or whether he is poor — whether he pleases man, or whether he gives offence — whether he is thought wise, or whether he is thought foolish — whether he gets blame, or whether he gets praise — whether he gets honour, or whether he gets shame — for all this the zealous man cares nothing at all. He burns for one thing; and that one thing is to please God, and to advance God’s glory.
If he is consumed in the very burning, he cares not for it — he is content. He feels that, like a lamp, he is made to burn; and if consumed in burning, he has but done the work for which God appointed him. Such a one will always find a sphere for his zeal. If he cannot preach, work, and give money, he will cry, and sigh, and pray. … If he cannot fight in the valley with Joshua, he will do the work of Mosus, Aaron, and Hur, on the hill (Exodus 17:9-13). If he is cut off from working himself, he will give the Lord no rest till help is raised up from another quarter, and the work is done. This is what I mean when I speak of ‘zeal’ in religion.
Bishop J. C. Ryle, Practical Religion, 1959 ed., p. 130