Third, there must be a personal appropriation of Christ as being all that He claims to be, John 1:12, 8:21, 24; 5:24. There must be surrender to a person, and not mere faith in a creed. Faith in a doctrine must lead to faith in a person, and that person Jesus Christ, if salvation is to be the result of such belief. So Martha was led to substitute faith in a doctrine for faith in a person (John 11:25).
It is such faith—consisting of knowledge, assent, and appropriation —that saves. This is believing with the heart (Rom. 10:9,10).
c) When Used in Connection with Prayer.
Three passages may be used to set forth this relationship: 1 John 5:14, 15; James 1:5-7, Mark 11:24. There must be no hesitation which balances between belief and unbelief, and inclines toward the latter—tossed one moment upon the shore of faith and hope, the next tossed back again into the abyss of unbelief. To "doubt" means to reason whether or no the thing concerning which you are making request can be done (Acts 10:20; Rom. 4:20). Such a man only conjectures; he does not really believe. Real faith thanks God for the thing asked for, if that thing is in accord with the will of God, even before it receives it (Mark 11:24). Note the slight: "that man."
We must recognize the fact that knowledge, assent, and appropriation exist here also. We must understand the promises on which we base our prayer; we must believe that they are worth their full face value; and then step out upon them, thereby giving substance to that which, at the moment may be unseen, and, perchance, nonexistent, so far as our knowledge and vision are concerned, but which to faith is a splendid reality.
d) When Used in Connection with the Word and Promise of God.
First, we should know whether the particular promise in question is intended for us in particular. There is a difference in a promise being written for us and to us. There are dispensational aspects to many of the promises in the Bible, therefore we must rightly divide, apportion, and appropriate the Word of God (cf. I Cor. 10:32).
Second, when once we are persuaded that a promise is for us, we must believe that God means all He says in that promise; we must assent to all its truth; we must not diminish nor discount it. God will not, cannot lie (Titus 1:2).
Third, we must appropriate and act upon the promises. Herein lies the difference between belief and faith. Belief is mental; faith adds the volitional; we may have belief without the will, but not faith. Belief is a realm of thought; faith is a sphere of action. Belief lives in the study; faith comes out into the market-places and the streets. Faith substantiates belief—gives substance, life, reality, and activity to it (Heb. 11:1). Faith puts belief into active service, and connects possibilities with actualities. Faith is acting upon what you believe; it is appropriation. Faith counts every promise valid, and gilt-edged (Heb. 11:11); no trial can shake it (11:35); it is so absolute that it survives the loss of its own pledge even (11:17). For illustration, see I Kings 18:41-43.