Any Answers from Christians?

Sure, God wants us to abide in Him and walk in His ways. Humans are never capable of doing so, though. Try as we might, we always mess up. We are all transgressors. EVERY SINGLE ONE OF US. And you know what the Quran says about transgressors.

I think of it like the laws of nature...this idea of atonement. When something evil is done, there must be atonement for it. Even the Orientals had the same idea with the yin-yang thing. The Egyptians had it with the scales of justice. I think even Islam has such a concept.

And yet no religion has provided the scales with which to weigh such debt. How is murder properly atoned for in the eyes of God? How is lying properly atoned for in the eyes of God? How about theft? Or what about the sins of the heart like lust and hate?

The plan for salvation was contingent upon humanity's sinfulness. But since God always knew humans would be sinful, then it doesn't sound like He was dependent on anything. Omniscience, remember?

If it weren't for humans sinning and then teaching the next generations to sin (and so forth), then salvation would not be necessary. The crucifixion is OUR FAULT!

Salvation is not guaranteed in Islam. You can hope and pray for it...fearing hell and begging for Jannah...Was Muhammad even sure? (Quran 46:9) And really, being a sinner as a Muslim doesn't matter. There are more than enough Christians and Jews to take your place. [Sahih Muslim, Book 37, Numbers 6665, 6666, & 6668]

That's what I never could understand about Islam. Can you sin or can't you? Are your good and bad deeds going to be weighed? How do you determine the individual weight of each deed so that you can keep track? If all you have to do is repent and make dua, then what is to keep you from sinning? If a Christian or Jew will take your place in hell, then what is to keep you from sinning? If Islam is the only guidance given by Allah, how do you know if you are doing things perfectly or not? Why must we follow Islam? Why won't Allah personally guide each one of us?

Natassia: Sure, God wants us to abide in Him and walk in His ways. Humans are never capable of doing so, though. Try as we might, we always mess up. We are all transgressors. EVERY SINGLE ONE OF US. And you know what the Quran says about transgressors.

The Quran says that all humans are born with a clean slate, unlike the Christian Bible.  My point was that in order for the plan of salvation to work, it required people to commit sin, something that the plan was trying to get rid of.  If this is not irony, I don't know what is.

Natassia: And yet no religion has provided the scales with which to weigh such debt. How is murder properly atoned for in the eyes of God? How is lying properly atoned for in the eyes of God? How about theft? Or what about the sins of the heart like lust and hate?

Islam has.  Atonement occurs in many ways.  Obviously, punishment according to the law is one way.  Other ways, as the Quran says, include asking for forgiveness, feeding the poor, freeing slaves, fasting, praying, giving charity etc. 

Natassia: The plan for salvation was contingent upon humanity's sinfulness. But since God always knew humans would be sinful, then it doesn't sound like He was dependent on anything. Omniscience, remember?

That's fine.  Of course the plan was contingent upon humanity sinfulness.  If they weren't sinful, they would not require salvation.  But there is a difference between salvation being contingent upon sinfulness and sinfulness being contingent upon salvation.  That is a big difference.  The Christian plan of salvation required sinfulness on the part of some people, which is why I also questioned Jesus could not have died in some other way, as long as death was the end result.  That is what I am concerned with. 

Natassia: If it weren't for humans sinning and then teaching the next generations to sin (and so forth), then salvation would not be necessary. The crucifixion is OUR FAULT!

Actually, according to your fellow Christian Douggg, we were born with a sinful nature.  So, how is that our fault?  It seems to me that it was really Adam and Eve's fault, since they were the ones who actually caused sin to permeate humanity in the first place. 

Natassia: Salvation is not guaranteed in Islam.

Says who?  The Quran says very clearly that if you believe in Allah and acknowledge that Muhammad (pbuh) is His messenger, then you will be saved:

O ye who believe! Obey Allah, and obey the Messenger, and those charged with authority among you. If ye differ in anything among yourselves, refer it to Allah and His Messenger, if ye do believe in Allah and the Last Day: That is best, and most suitable for final determination.(4:59)

The only difference is that a Muslim is also told to do good deeds and avoid bad deeds.  When a Muslim dies, his deeds are weighed against each other and if the bad deeds are more numerous, then the Muslim is sent to Hell...but not for eternity!  This is made clear by the saying of the blessed prophet Muhammad (pbuh) as mentioned in Sahih Bukhari:

"Narrated Abu Said Al-Khudri:

The Prophet said, "When the people of Paradise will enter Paradise and the people of Hell will go to Hell, Allah will order those who have had faith equal to the weight of a grain of mustard seed to be taken out from Hell. So they will be taken out but (by then) they will be blackened (charred). Then they will be put in the river of Haya' (rain) or Hayat (life) (the Narrator is in doubt as to which is the right term), and they will revive like a grain that grows near the bank of a flood channel. Don't you see that it comes out yellow and twisted""

So, yes a Muslim is saved in the end.  The only difference between our view and yours is that if you were to ask a Muslim the question "are you saved", the response would be "InshaAllah" or "God willing", whereas the Christian response to such a question would be "Yes, definitely!"  That is because salvation in Islam is ultimately based on God's mercy, not on our own whims.  We will not say "Yes, definitely" because that would be assuming the role of God, who is the one who ultimately decides who is saved and who is not. That is not the same as being "unsure" of salvation. 

Natassia: You can hope and pray for it...fearing hell and begging for Jannah...Was Muhammad even sure? (Quran 46:9)

Yes, he was.  But, because he was humble and truly gracious to his Lord, he prayed, asked for forgiveness and shed tears profusely.  This is indicated by the testimony of Hazrat Aisha (ra):

Narrated Aisha:

The Prophet used to offer prayer at night (for such a long time) that his feet used to crack. I said, "O Allah's Apostle! Why do you do it since Allah has forgiven you your faults of the past and those to follow?" He said, "Shouldn't I love to be a thankful slave (of Allah)?' When he became old, he prayed while sitting, but if he wanted to perform a bowing, he wound get up, recite (some other verses) and then perform the bowing.

In addition, when he knew his death was near, he indicated that the Lord would welcome him with open arms:

Narrated Abu Said Al-Khudri:

The Prophet delivered a sermon and said, "Allah gave a choice to one of (His) slaves either to choose this world or what is with Him in the Hereafter. He chose the latter." Abu Bakr wept. I said to myself, "Why is this Sheikh weeping, if Allah gave choice to one (of His) slaves either to choose this world or what is with Him in the Here after and he chose the latter?" And that slave was Allah's Apostle himself. Abu Bakr knew more than us. The Prophet said, "O Abu Bakr! Don't weep. The Prophet added: Abu- Bakr has favored me much with his property and company. If I were to take a Khalil from mankind I would certainly have taken Abu Bakr but the Islamic brotherhood and friendship is sufficient. Close all the gates in the mosque except that of Abu Bakr.

Natassia: That's what I never could understand about Islam. Can you sin or can't you? Are your good and bad deeds going to be weighed? How do you determine the individual weight of each deed so that you can keep track? If all you have to do is repent and make dua, then what is to keep you from sinning?

I have answered these questions.

Natassia: If a Christian or Jew will take your place in hell, then what is to keep you from sinning?

The fear of Allah and faith in His message.  The throwing of the unbelievers into Hell will be an act of mercy upon the believers who had a heavy debt of sinful behavior (#6668).  That does not mean that a Muslim can go on sinning, because Allah says not to sin.  So, if we do it, would would be disobeying Allah and that is never good.  Also, notice that in #6669, the sinner Muslim is asked by Allah if he acknowledges his sins.  When the Muslims admits his sins, instead of trying to make excuses, Allah will reward his humbleness by forgiving his sins:

Safwan b. Muhriz reported that a person said to Ibn 'Umar: How did you hear Allah's Messenger (may peace be upon him) as saying something about intimate conversation? He said: I heard him say: A believer will be brought to his Lord, the Exalted and Glorious, on the Day of Resurrection and He would place upon him His veil (of Light) and make him confess his faults and say: Do you recognise (your faults)? He would say: My Lord, I do recognise (them). He (the Lord) would say: I concealed them for you in the world. And today I forgive them. And he would then be given the Book containing (the account of his) good deeds. And so far as the non-believers and hypocrites are concerned, there would be general announcement about them before all creation telling them that these (people, i. e. non-believers and hypocrites) told a lie about Allah.

Natassia: If Islam is the only guidance given by Allah, how do you know if you are doing things perfectly or not? Why must we follow Islam? Why won't Allah personally guide each one of us?

You follow to the best of your ability the Quran and Sunnah.  And, yes Allah does guide us as He wills.  But, that is based upon our own actions.  He only guides those who are faithful and truly yearn to do good and follow Him.