“I KNOW that my Redeemer liveth.”
“This was not a mere speculative knowledge of the Messiah, which he might have by special revelation, as Balaam had, or from the first intimation of him, as the seed of the woman, that should bruise the serpent’s head, to our first parents; which was, no doubt, traditionally handed down to Job’s time; but Job not only knew that there was a Redeemer promised, that he then existed, but he knew him to be his Redeemer. Nor was this knowledge only a knowledge of approbation. Those who savingly know Christ, do approve of him above all other persons or things in heaven or in earth; he is to them the chiefest among ten thousand: They value him for his personal excellencies, and proper qualifications to be a Redeemer; they like and approve of him to be theirs, as did Job, when he said, He also shall be my salvation. (Job 13:26.)
But then this was not all, he not only approved of him as a Redeemer, but he knew him to be his. Nor was this knowledge only a fiducial one; they that know his name, his person, blood and righteousness, will put their trust in him; and as their knowledge of him increases, their confidence in him will grow. And such a trust was reposed in him by Job, who could say, Though he slay me, yet will I trust in him; (Job 13:15.) but he does not stop here, he mounts the highest step in the ladder of faith, and rises up to a full assurance of it; he could say as the apostle Paul long after did, under greater light, and larger discoveries of Christ; I know whom I have believed; and I am persuaded; that he is able to keep that which I have committed to him against that day. (2 Timothy 1:12.) The doctrine of assurance is decried by Papists, and now-a-days discouraged by many who are called Protestants, and understood experimentally by a very few. It is true, indeed, that for a man to know his interest in Christ, and title to heaven, is the highest pitch of grace he arrives to here; yet this may be attained under the influences of the Spirit of God, without an extraordinary revelation, as is objected.
You will say, how do any know their interest in Christ, or that he is their Redeemer? I answer, this may be, and is known, from the inhabitation of the Spirit in them, Hereby we know, that we dwell in him, and he in us, because he hath given us of his Spirit. (Job 4:13.) This known also from the testimony of the Spirit witnessing with their spirits, that they are the children and heirs of God, and co-heirs with Christ; and from the work of the spirit upon their souls, which is a fruit and effect of redeeming grace; and from the benefits of redemption being applied to them, such as righteousness, pardon of sin, atonement, and the like; this is certain, that they to whom the blessings of redemption are applied, are interested in the Redeemer, who may justly conclude, from their receiving the earnest of the redemption of the purchased inheritance, that they shall enjoy the whole: The connection between grace and glory is inseparable, and he that has the one may be sure of the other. So much for the first article of Job’s faith.” – John Gill