6 But let him ask in faith. He shews here, first the right way of praying; for as we cannot pray without the word, as it were, leading the way, so we must believe before we pray; for we testify by prayer, that we hope to obtain from God the grace which he has promised. Thus every one who has no faith in the promises, prays dissemblingly. Hence, also, we learn what is true faith; for James, after having bidden us to ask in faith, adds this explanation, nothing wavering, or, doubting nothing. Then faith is that which relies on God’s promises, and makes us sure of obtaining what we ask. It hence follows, that it is connected with confidence and certainty as to God’s love towards us. The verb διακρίνεσθαι, which he uses, means properly to inquire into both sides of a question, after the manner of pleaders. He would have us then to be so convinced of what God has once promised, as not to admit a doubt whether he shall be heard or not.
He that wavereth, or doubteth. By this similitude he strikingly expresses how God punishes the unbelief of those who doubt his promises; for, by their own restlessness, they torment themselves inwardly; for there is never any calmness for our souls, except they recumb on the truth of God. He, at length, concludes, that such are unworthy to receive anything from God.
This is a remarkable passage, fitted to disprove that impious dogma which is counted as an oracle under the whole Papacy, that is, that we ought to pray doubtingly, and with uncertainty as to our success. This principle, then, we hold, that our prayers are not heard by the Lord, except when we have a confidence that we shall obtain. It cannot indeed be otherwise, but that through the infirmity of our flesh we must be tossed by various temptations, which are like engines employed to shake our confidence; so that no one is found who does not vacillate and tremble according to the feeling of his flesh; but temptations of this kind are at length to be overcome by faith. The case is the same as with a tree, which has struck firm roots; it shakes, indeed, through the blowing of the wind, but is not rooted up; on the contrary, it remains firm in its own place.