Job 19:25-26 are some of the best known words from the Book of Job, having been popularised by Handel’s Messiah
25 For I know that my Redeemer lives,
and at the last he will stand upon the earth.
26 And after my skin has been thus destroyed,
yet in my flesh I shall see God,
27 whom I shall see for myself,
and my eyes shall behold, and not another. (ESV)
It is usual for Christians to read this as prophetic words by Job, referring to his future resurrection, to interpret “redeemer” as a reference to the Messiah, Jesus, and to see this as Job’s vindication at last in the Final Judgment.
The Hebrew word translated “redeemer” is גאל go’el and is used most frequently in Isaiah (24 times) with reference to the God of Israel. So it appears on the surface that Job is expressing his confidence in God and his assurance of eternal salvation. The word is translated in various ways, including “my Avenger” (Leslie Wilson), and “my vindicator” (JPS and Marvin Pope). Some scholars see the words “engraved in rock” in the previous two verses to be a permanent and continuing vindication of Job, and hence his go’el. Some see The Vindicator as a sort of counterpart to The Prosecutor (ha-satan) who accused Job in the Prologue, Job’s Defence Counsel. If so, his identity is unknown.
It is possible that there are two forensic terms here: גאל go’el and אחרון akharon (translated “at the last” in the ESV). Both terms appear in parallel in Isaiah 44:6 and Marvin Pope notes the Talmudic and Mishnaic usage of the related term אחראי in the sense of ‘guarantor’ . אחרון acharon literally means “the last (one)” and in a forensic sense refers to a guarantor, the last resort for payment. Many commentators, however, read this as an eschatalogical reference to “the last days” (although “days” is unstated) and hence interpret this as an after-death resurrection experience. It could just as easily mean “at the end” or “at last”(in the sense of “eventually”).
Robert Sutherland  also understands the Hebrew word קום qum (“he will stand” ESV) as ‘a legal term meaning “to stand up in court” as an “advocate”.’ If he is correct then this reinforces the forensic nature of the text. In fact, as Norman Habel has rightly pointed out, the whole of the Book of Job is “a legal metaphor”. The idea of a lawsuit against God was first mooted in Job’s second speech in the second cycle, and here he continues the theme by expressing his desire that a Vindicator or Advocate will eventually stand up to argue his case. This fits with his previous longing for an advocate (Job 9:33; 16:19). Sutherland argues that this Advocate is none other than God himself and sees no difficulty in God being the Judge, the Advocate and the Defendant all at once. “Job’s complaint has become an appeal to God, through God and against God” . I personally don’t find Sutherland’s argument here convincing. To me this text reads more naturally as Job saying “I am confident that eventually someone will stand up and speak in my defence and vindicate me [my Vindicator and Guarantor], and that I will have my day in court.” Interestingly, Job’s vindication happens, unexpectedly, at the end of the book, but without the appearance of an Advocate.
I personally don’t see any evidence here that Job was expressing his hope in a resurrection, or that his vindication would come after his death, especially as he later refers to the terrors and finality of death (23:14-17; 26:6; 30:23). The Hebrew Bible has very little to say about the afterlife and Psalm 16:10-11; 49:15; 73:27-28; Isaiah 26:19 and Daniel 12:2 are probably the only texts which refer with any certainty to an afterlife. In the context, it would be odd if Job was here putting his hope in vindication in an afterlife. As P.S. Johnston has rightly pointed out :
‘Job still continues his legal argument after chapter 19: he wants to find God, present his case, be acquitted, be tested and emerge like gold (Job 23:3-10). His defiant summation still longs for fair judgment and a divine hearing (Job 31:6, 35). What Job “knows” in Job 19:25 affects neither this subsequent argumentation nor the closing chapters of the book …’
Some commentators argue that the words “after my skin has been thus destroyed” necessitate a reference to resurrection. It could equally be a reference to his extreme suffering and physical deterioration . And while scholars differ as to whether מבשרי mib’sari means “in my flesh” or “without my flesh” the context seems to demand, as Gerald Wilson puts it, “that Job would be expressing in these verses his heartfelt desire that even though he has come so close to death and has almost no hope left, that even now – in this life – God might appear and provide vindication.” 
I do not see this text as eschatalogical or messianic. My reading of these verses therefore would along these lines:
“I am confident that eventually someone will stand up and speak in my defence and vindicate me, and that I will have my day in court. But I want to face God myself while I am still alive, and not be defended by an unknown advocate after I am dead.”
Job got his wish: the LORD soon speaks from the whirlwind, and Job is vindicated.
 Pope, M., Job: A New Translation with Introduction and Commentary, Anchor Bible Vol. 15, 3rd edition, (New York: Doubleday and Co. 1974), 146
 Sutherland, R., Putting God on Trial: The Biblical Book of Job 2004, p57
 Sutherland, 2004, p58
 Johnston, P., “Afterlife” in T. Longman and P. Enns (eds), Dictionary of the Old Testament: Wisdom, Poetry and Writings (Downers Grove: Intervarsity, 2008), 6
 See Wilson, G., Job New International Biblical Commentary (Peabody: Hendrickson, 2007), 209