From A. W. Pink’s Exposition of the Gospel of John:
From what has been said, it will be evident that when God told Moses to make a serpent of brass, fix it upon a pole, and bid the bitten Israelites look on it and they should live, that He was preaching to them the Gospel of His grace. We would now point out seven things which these Israelites were not bidden to do.
1. They were not told to manufacture some ointment as the means of healing their wounds. Doubtless, that would have seemed much more reasonable to them. But it would have destroyed the type. The religious doctors of the day are busy inventing spiritual lotions, but they effect no cures. Those who seek spiritual relief by such means are like the poor woman mentioned in the Gospel: she “suffered many things of many physicians, and had spent all that she had, and was nothing bettered, but rather grew worse” (Mark 5:26).
Although Pink signed his Foreword with a date of 1923, this reads as if he were talking about today (much like Machen’s monumental Christianity and Liberalism). What a great reminder: if you’re hearing something called “the Gospel,” and it sounds reasonable, guess what — it’s not the Gospel! But the foolishness of “Just look at the Cross!” — that’s the Gospel.