The first problem is that a child of God will not continue to sin so any claim for a pre-mortal to be a child of God and then enter into sin makes his claim invalid. This is the same as light changing to darkness it doesn't happen, light is always light and cannot be anything but light. God is light in Him is no darkness so this now makes the claim that God changes occasionally because you are attaching His seed to a pre-mortal that changes from light to darkness.
Do you have any scripture to back this up?
In non-LDS belief, God is our creator. That makes us children of God. The only difference between LDS and non-LDS doctrines in this matter is that we believe that we existed before this mortal life.
As creations (children) of God I have seen nothing that indicates that we would not sin. We made the decision to enter mortality, where we could be tempted, and where we could make the decision to follow God under adverse circumstances.
We have the light of God within us. It has not changed to darkness. We know right from wrong. You seem to be replacing our existence as enlightened beings and the ability to make choices with this analogy of light and dark. We are not physically light.
We are children. And as children, we have not fully developed. We are not fully grown. This earthly existence allows us to grow to adults.
The Bible makes no claim that a child of God will sin.
What does it say on the matter?
Christianity teaches that man is born into sin by the actions of one man and men are redeemed by the actions of one man. Christ came to save his people from their sin (Matthew 1:21).
Okay.
Now after a man is washed by Christ, for Christ said, "Unless I wash you, you have no part with me". That is the rebirth and the washing of regeneration by the Holy Spirit now he is a new creation. Will he sin again?
Man is imperfect. Even after we are reborn we make mistakes. Fortunately, the atonement allows us to recover from those mistakes. This statement of yours here is faulty. It implies a level of perfection once we are reborn that doesn't exist in anyone except the Savior. Other than Christ, the only person that doesn't sin again is someone who has passed on.
Christ said, speaking to the apostles, "A person who has had a bath needs only to wash his feet; his whole body is clean." Yes, but when he passes through final judgement and the blood of Christ has taken the penalty for his sin, through his now proven faith, then that man and Christ will become one flesh(Eph 5). That man will never go back to sin because God's seed remains in him through Christ and he is now a Child of God, yet he is already called a child of God because of foreknowledge.
This backs up my previous statement. This speaks of a bath and thereafter a washing of the feet. A great cleansing that leaves us needing only lesser cleansings thereafter. If we no longer sinned, then these lesser cleansings would be unnecessary.
"Whoever believes in him is not condemned, but whoever does not believe stands condemned already because he has not believed in the name of God's one and only Son." There is only one Son of God that is why Abraham was not before Christ, thus; "Before Abraham was, I AM."
I'm not following you here. Christ is the only begotton Son of God in the flesh. And this is a different relationship than I previously described. We are children of God because He created us. That is not the same situation as Christ.
This is the other problem, why would they ever depart?
I already explained that. We have left so that we may continue to mature.
Personally, I think it would be irrelevant where we spend eternity the Garden of Eden or Heaven, hell excluded
, as long as I am in the presence of God.
That's your choice to believe that.
There is nothing greater than the fellowship and worship with and of God, yet I speak of worship concerning spirit and truth. Beholding the glory of the Lord is better than any gift you can receive.
Again, that is your choice to believe that.
What are rewards compared to the presence of the Almighty?
The opportunity to grow to become like the Almighty. The opportunity to follow His plan for our happiness. The ability to gain a physical body and all the joys that are associated with that. The joy of knowing that when our intimate knowledge of Him was taken away we still chose to be in His presence.
The one who gave us the ability to thirst, to desire, to have, to love, to understand. Did not Paul say, to live is Christ and to die is gain?
I don't know, did he?
I ask again why would a creature having access to the presence of God choose a mortal existence and excommunication for a fleshly reward?
I have answered that several times. No need to keep asking. Except, that this is not excommunication. That is a term you have applied to it because you reject the idea and want it to sound undesireable.
Wouldn't such a creature would be no different than the sons of Belial in that matter? Was Satan not the one who desired apart from God and didn't that cause his fall?
I'm unsure of what you are saying here. Satan's fall is due to his wanting to promote a different plan than the one Heavenly Father devised, so that he could bring glory to himself, rather than the Father. It dealt with the taking away of free will and the ability to make meaningful choices in this life.
I don't deny life is a test to reveal our quality, Deut 13:3 as well as many other scriptures give light to that. However, the only experience a pre-mortal would learn is that his new heart of flesh is deceitful above all else and desperately wicked beyond understanding.
You may choose to limit your vision of what can be learned in this life if you wish, but I know that there is a great deal more to be learned than what you have suggested. I have already learned more than what you have suggested.
They would have no hope of God apart from His mercy to reveal Himself to them. Yet, have they not chosen poorly and forsaken the Lord to gain a carnal mind?
This has already been answered. They have subjected them to a testing ground that will allow them to make a meaningful choice to accept God.
What merit do they earn from this?
Answered.
I don't have to live a year in the trash to know it stinks or commit murder to know its wrong. Yet they are worse than murders by doing this for they know better and still decide to become lawbreakers. By choosing mortality are they not choosing death and revealing their true depravity? And for what purpose, the sake of experience? Or a body with its sensual desires and carnal thoughts which God hates? Furthermore they have now forsaken holy living and without holiness no man will see God. Forgive me but that still seems both idle and wicked.
You talked first about light. And that is what we gain in mortality - an enlightenment that we can obtain in no other way. We grow as adults through our experiences here. Sensationalizing the negative in this manner doesn't change any of that.
And you talk about forsaking holy living, but many of us seek holy living. We haven't forsaken it. Otherwise, as you stated, none of us could possibly see God. And the truth is that each of us have the possibility to be with God again. It is all based on our choices here.
Forgive me as well, but I find it silly to bring up being idle as a negative when you have promoted the same. Remaining with Heavenly Father, we were idle (as in not progressing). This experience is so that we will not be idle. God commanded Adam and Eve to be fruitful and multiply. And well it is that He did, because that is what it takes for us not to be idle. And that is exactly the reason why we have all chosen this earthly journey, so that we can grow to lead truly meaningful lives instead of idly standing around God and selfishly taking from Him rather than giving our best effort.
but that is the real issue in every "profession" that makes it all meaningless.
arrogance, Please shed.
Love 
& JOY 
