Question: Bob; How is it that Satan who is pure evil, can appear and accuse the brethren before a holy God, but man cannot stand before Him lest he die.
Response: A difficult question. We will stand before God, and will live with Him and His Son, our Lord Jesus Christ, forever. That, of course, will not happen while we are in these present bodies. That is possible only after we have been resurrected and possess perfect, holy bodies. We do know (from Job 1-2 for example) that the devil does continue to appear before God and complain about believers, even though he has already been judged (cf. Jn.16:11) - and we are told of no physical or corporal transformation of Satan and his demons as a consequence of their rebellion. Man, on the other hand, was created perfect and did have "face to face" fellowship with God in Eden (cf. Gen.2:16; 219; 2:22; 3:8-10). Given what Isaiah says when he sees the Lord - "woe is me ..... for I am man of unclean lips and I live among a people of unclean lips and my eyes have seen the king, the Lord Almighty" (Is.6:5) - it seems to me that if one is trying to find a solution to this problem it will be found along these lines. That is to say, mankind, physically corrupt (with a sin nature) as a result of the fall, is an unholy thing and nothing unholy can stand in the presence of a holy God. Isaiah is relieved of his fear when he is "cleansed" by a coal from the altar, a clear symbol of judgment transferred: he is not burned, it is left for Another to take the punishment for his sin. So we who have been purified in our hearts cannot stand before God until we are bodily cleansed by the transformation of our mortal flesh, while the devil and his angels, having no such bodily corruption, are permitted into the presence of the Lord (although they are corrupt in their hearts) - that this internal truth is ultimately much more important is very clear, because they will soon be thrust out of His presence forever (Rev.12:7-10), but we will soon be with Him forevermore (Rev.21-22). And all this is necessary for the furtherance of God's plan. It is both necessary for our adversaries to continue to have access to God and to have the freedom to oppose and accuse us for a time (that it may be made clear for whom we have chosen), and necessary as well for us to be kept now for a time out of the presence of God (so that we may choose in true freedom: were we to see God as He is, no one could fail to worship Him). See also: How is Satan Allowed to Appear before God?
For the admission of departed believers into heaven on the basis of Christ's resurrection, ascension and session, and for our prayer access to the Father on the basis of Christ's sacrifice on our behalf, please see the following links:
The Transfer of Believers from the Subterranean Paradise to the Third Heaven
Access and Intercession
Yours in Christ,