Whenever there is a real revelation of God to anyone, the conscience is always reached and the heart affected. There is never any light from God without love.
We never know anything about God with the mind, except that we cannot know Him. All true knowledge humbles, because it brings something of God to me that I did not know before. It finds in me something contrary to it; truth is perfectly divine and heavenly in its character, yet suited to me. It brings what is heavenly, and shows me I am not that and humbles me.
In the case of the thief on the cross, the light shines in and we see the effect: "Dost not thou fear God, seeing thou art in the same condemnation? And we indeed justly." Truth is of no use until it is subjective, or until it affects me, otherwise it is only a matter of memory.
Church truth may be held by one who does not know what it is to be in the Spirit; then it is only a matter of memory. The Holy Spirit does not merely say there is a Church, but that we are members of His body, of His flesh, and of His bones. It is not a mere dogma. The tendency with us is to make theology, and not to be affected by what Scripture says. It is not merely a statement, but God connects it livingly with the heart and affections.
Another important thing is that the actual condition of a soul be such that we are able to receive truth. At Corinth the Apostle fed them with milk; they were not able to take strong meat. So also in Hebrews. We need to bear this in mind. If we talk to a person about truth that he is not in a state to receive, we may puff him up.
If a Christian walks unfaithfully, he may lose even what he knows. All living truth becomes a part of ourselves like food. It is said, "if any man thirst," and then it speaks of coming out of his belly, that is, out the very inmost part of the man himself. I do not believe anyone has got the truth unless it has engaged his affections to Christ and moved his conscience.