I found the following passage from Mr. Ryle's tremendously edifying book "Knots Untied" to be most helpful in grasping the ways in which true evangelical religion may be perverted subltely, unwitingly or outright craftily:
It only remains for me to say a few words on the last question I propose to consider:—“What is it that makes much religion appear to us not Evangelical?”
This is no doubt a delicate point, but a very serious and important one. I repeat here what I have remarked before. We do not say that men who are not professedly Evangelical ignore and disbelieve the leading doctrines of the Evangelical creed. We say nothing of the kind. But we do say confidently, that there are many ways in which the faith of Christ may be marred and spoiled, without being positively denied. And here we venture to think is the very reason that so much religion called Christian, is not truly Evangelical. The Gospel in fact is a most curiously and delicately compounded medicine, and a medicine that is very easily spoiled.
You may spoil the Gospel by substitution. You have only to withdraw from the eyes of the sinner the grand object which the Bible proposes to faith,—Jesus Christ; and to substitute another object in His place,—the Church, the Ministry, the Confessional, Baptism, or the Lord's Supper,—and the mischief is done. Substitute anything for Christ, and the Gospel is totally spoiled! Do this, either directly or indirectly, and your religion ceases to be Evangelical.
You may spoil the Gospel by addition. You have only to add to Christ, the grand object of faith, some other objects as equally worthy of honour, and the mischief is done. Add anything to Christ, and the Gospel ceases to be a pure Gospel! Do this, either directly or indirsctly, and your religion ceases to be Evangelical.
You may spoil the Gospel by interposition. You have only to push something between Christ and the eye of the soul, to draw away the sinner's attention from the Saviour, and the mischief is done. Interpose anything between man and Christ, and man will neglect Christ for the thins interposed! Do this, either directly or indirectly, and your religion ceases to be Evangelical.
You may spoil the Gospel by disproportion. You have only to attach an exaggerated importance to the secondary things of Christianity, and a diminished importance to the first things, and the mischief is done. Once alter the proportion of the parts of truth, and truth soon becomes downright error! Do this, either directly or indirectly, and your religion ceases to be Evangelical.
Lastly, but not least, you may completely spoil the Gospel by confused and contradictory directions. Complicated and obscure statements about faith, baptism, Church privileges, and the benefits of the Lord's Supper, all jumbled together, and thrown down without order before hearers, make the Gospel no Gospel at all! Confused and disorderly statements of Christianity are almost as bad as no statement at all! Religion of this sort is not Evangelical.
I know not whether I succeed in making my meaning clear. I am very anxious to do so. Myriads of our fellowcountrymen are utterly unable to see any difference between one thing and another in religion, and are hence continually led astray. Thousands can see no distinct difference between sermons and sermons, and preacheis and preachers, and have only a vague idea that “sometimes all is not right.”
I will endeavour, therefore, to illustrate my subject by two familiar illustrations. A doctor's prescription of a medicine often contains five or six different ingredients. There is so much of one drug and so much of another; a little of this, and a good deal of that . Now what man of common sense can fail to see that the whole value of the prescription depends on a faithful and honest use of it? Take away one ingredient, and substitute another; leave out one ingredient altogether; add a little to the quantity of one drug; take away a little from the quantity of another. Do this, I say, to the prescription, my good friend, and it is a thousand chances to one that you spoil it altogether. The thing that was meant for your health, you have converted into downright poison.
Apply this little simple parable to the Gospel. Regard it as a medicine sent down from heaven, for the curing of man's spiritual disease, by a Physician of infinite skill and power; a medicine of singular efficacy, which man with all his wisdom could never have devised. Tell me now, as one of common sense, does it not stand to reason that this medicine should be used without the slightest alteration, and precisely in the manner and proportion that the great Physician intended? Tell me whether you have the least right to expect good from it, if you have tampered with it in the smallest degree?
You know what the answer to these questions must be: your conscience will give the reply. Spoil the proportions of your doctor's prescription, and you will spoil its usefulness, even though you may call it medicine. Spoil the proportions of Christ's Gospel, and you spoil its efficacy. You may call it religion if you like; but you must not call it Evangelical. The several doctrines may be there, but they are useless if you have not observed the proportions.