But he knoweth the way that I take: when he hath tried me, I shall come forth as gold. My foot hath held his steps, his way have I kept, and not declined. Neither have I gone back from the commandment of his lips; I have esteemed the words of his mouth more than my necessary food.--(Job 23:10-12)

When have we learned a doctrine?

My brethren, this is a lesson for us; let us never reckon that we have learned a doctrine till we have seen its bearing upon our lives. Whatever we discover in God’s word, let us pray the Holy Spirit to make us feel the sanctifying influence of it. You know not a man because you recognize his features, you must also know his spirit, and so the mere acquaintance with the letter of truth is of small account — you must feel its influence and know its tendency.

There are some brethren who are so enamored of doctrine that no preacher will content them unless he gives them over and over again clear statements of certain favourite truths: but the moment you come to speak of practice they fight shy of it at once, and either denounce the preacher as being legal, or they grow weary of that which they dare not contradict. Let it never be so with us. Let us follow up truth to its practical “therefore.” Let us love the practice of holiness as much as the belief of the truth; and, though we desire to know, let us take care when we know that we act according to the knowledge, for if we do not our knowledge itself will become mischievous to us, will involve us in responsibilities, but will bring to us no effectual blessing. Let everyone here who knoweth aught, now pray God to teach him what he would have him to do, as the consequence of that knowledge.

From a sermon by Charles Haddon Spurgeon entitled "Motives For Steadfastness," delivered May 11, 1873.