It is significant that here, in what is probably the oldest book in the Bible, two vitally important New Testament truths are anticipated. Job somehow knew that he (and, by implication, every other person as well) has a "record" in heaven. This is the only occurrence of this word (sahed) in the Bible, but it basically means that our works, good or bad, have been recorded by God in heaven concerning how we have used or abused our stewardship here on earth.
And the record, inevitably, testifies against us, "for there is not a just man upon earth, that doeth good, and sinneth not" (Ecclesiastes 7:20). At God's future throne of judgment, when "the dead |are| judged out of those things which were written in the books, according to their works," then "whosoever |is| not found written in the book of life |is| cast into the lake of fire" (Revelation 20:12, 15).
But how can we know that our names will be in God's book of life in that day? Thankfully, even Job knew, in his long-ago time, that "my witness is in heaven." Here the word (Hebrew ed) speaks of a formal personal witness who can testify on our behalf, one who "might plead for a man with God, as a man pleadeth for his neighbor!" (Job 16:21).
Job somehow knew that such a witness was there, for he could also say, "I know that my redeemer liveth" (Job 19:25). In the light of the New Testament record, we know that this Redeemer and Witness is none other than the Lord Jesus. "If any man sin, we have an advocate with the Father, Jesus Christ the righteous: And he is the propitiation for our sins" (1 John 2:1-2). That is, He is the "sacrifice" for our sins, and thus can redeem us from sin's penalty, and thereby serve as our defense witness in heaven. Our record of sin and guilt has been washed clean with the precious blood of Christ. HMM http://www.icr.org/article/6141/