The distinction seems to be in the definition (and we know that definitions are the driving element behind true understanding). In the Bible, "sinless" means "never sinned and does not have a sin nature." In the Qur'an, "sinless" seems to mean "I sinned but I've been forgiven and cleansed, so it's as if I never sinned." Those are completely different things.

But now let's take it a step further. The Bible says Jesus never sinned and does not have a sin nature. The Qur'an calls Isa (Jesus) "holy," a term it never uses for Muhammad. The Qur'an never claims that Jesus ever did anything wrong, or ever sinned. And yet the Qur'an claims, and Muhammad himself claims, that Muhammad was not sinless, but only forgiven and cleansed by Allah. So all prophets are "sinless" in that they have been cleansed, but Isa is "sinless" in that he never sinned and never needed cleansing.

The word is "Zakiya" - Purified, Clean, etc. And it's the truth because all prophets are sinless - they are forgiven of their sins and admitted to heaven with no problem. They may commit very minor sins in their life but they are all forgiven. They are exempted.

Everyone has already posted in regards to the Prophet Muhammad(saw) being the greatest among the Prophets. He is among the 5 greatest prophets(as) including Moses(as), Jesus(as), Abraham(as), and Nuh(as). The verse being cited about no distinction between the Prophets(as) is referring to no distinction between their message about God and that we should not discriminate between them. However, Allah(SWT) has still enjoined different positions among his Prophets(as).
With regards to being sinless, you might be getting conflicting answers because there are two opinions on the issue.

One opinion is that the Prophets(as) were completely free from any type of sin, major or minor, and they they only committed mistakes.

The other opinion is that the Prophets(as) were free from major sins, but they could still commit minor sins. They would never insist on these sins and immediately repent. This opinion is mentioned by Ibn Taymiyyah(ra) as the majority opinion and the majority opinion among the other main theological school as well.

Both opinions agree on the Prophet Muhammad(saw)'s infallibility in delivering the message and it was completely free of error.

As far as miracles, the Prophet(saw) performed many miracles just as Jesus(as) did, by the permission of Allah(SWT).

Some miracles include:

The Qur'an (which is the greatest miracle provided to him)
The temporary splitting of the moon
Providing a miraculous amount of food to feed hundreds-thousands people from handfuls.
His numerous prophesies which came true such as the Muslim conquering of Syria and Yemen which he prophesized when they were completely downtrodden and with only a handful of followers.
Comforted a crying tree (this hadith is actually a mutawattir hadith of the Nabi(saw))
Miraculously cured some illnesses

'Isa (as) is called zakiyya, which means cleansed or purified from sin, the same as the prophet Muhammad (sawa) and all other prophets sent by God. It's a necessary part of being a prophet that they not commit sin, otherwise how would one be required to obey them?

Holy, as in sacred or sanctified, is muqaddas, and no prophet is called that in the Qur'an. Only Allah is called Quddus (the most sacred, purified and holy).

> Am I understanding you? Obviously, through the years we have all heard stories of Muhammad's violent military conquests and his multiple wives, including a young girl. Are these all untrue rumors? Or were they right and perfect in Allah's eyes?

Yes, he did have military conquests, yes multiple wives as well, and yes one of them was young in age. And yes, these were all good and approved in Allah's eyes.

If you have questions after reading, I'll be happy to answer.

Many Muslims believe that Muhammad (SAW) was sinless, as was every other Prophet.
All Muslims believe that Prophet Muhammad (SAW) did in fact do miracles.

I'm trying now to summarize this, because I'm still confused. I asked, “Islam teaches that Muhammad is the last and greatest prophet. I am asking how that can be if Isa was sinless, and Muhammad was not, and if Isa did miracles, but Muhammad did not."

I am getting a lot of different answers:

The Qur’an does say Muhammad is the Seal of the Prophets, meaning he is the last prophet, and the Qur’an does say that he is the greatest prophet (S. 2.253; 17.55). But it sounds also as if the Qur’an says Muslims are not to distinguish between prophets (S 2.136), and that Muhammad refused to be considered higher than the other prophets.

As far as miracles, most claim that Muhammad never performed a miracle, but that the bringing of the Qur’an was the miracle he performed. But then someone else said Muhammad had done miracles.

But the idea of whether or no Muhammad had sinned is really confusing me, the way Muslims seem to be defining sin:

“Both Muhammad and Jesus were sinless (see S. 53.1ff.)."
“When Muhammad was a child, Gabriel washed the sins out of his heart.”
“No one is sinless (not Muhammad or Jesus). Forgiveness must always be sought from Allah.”
“Prophets never sin, but when they do something that isn’t the absolute best, it is considered a sin.”

Then in Sahih Bukhara, Hadith 5919, Muhammad asks forgiveness for his sins, but he didn’t need to because Allah had already forgiven him, and even though he had small human errors from the limitations of being human, Muhammad was sinless because he never disobeyed Allah.

I am CONFUSED. Can you help me understand?

Quran 2:253
تِلْكَ الرُّ‌سُلُ فَضَّلْنَا بَعْضَهُمْ عَلَىٰ بَعْضٍ

"Of those messengers, some of whom We have caused to excel others"

Quran 17:55
وَلَقَدْ فَضَّلْنَا بَعْضَ النَّبِيِّينَ عَلَىٰ بَعْضٍ

"And We have made some of the prophets exceed others [in various ways]"

These two verses clearly show us that there's some kind of hierarchy between the prophets. In another verse of the Quran, there's a mention to "Ulu Al 'Azm" (فَاصْبِرْ‌ كَمَا صَبَرَ‌ أُولُو الْعَزْمِ مِنَ الرُّ‌سُلِ Quran 46:35), which refers (for most views) to the five greatest messengers: Muhammad, Ibrahim, Musa, Issa and Nuh عليهم الصلاة والسلام.

These two verses are informative, there's no command here. Allah is informing us that He has given to some prophets a special rank or superiority (and indeed, we consider Muhammad صلى الله عليه وسلم to be at the highest rank).

But Allah also commands us to not discriminate between them:

Quran 2:136
قُولُوا آمَنَّا بِاللَّـهِ وَمَا أُنزِلَ إِلَيْنَا وَمَا أُنزِلَ إِلَىٰ إِبْرَ‌اهِيمَ وَإِسْمَاعِيلَ وَإِسْحَاقَ وَيَعْقُوبَ وَالْأَسْبَاطِ وَمَا أُوتِيَ مُوسَىٰ وَعِيسَىٰ وَمَا أُوتِيَ النَّبِيُّونَ مِن رَّ‌بِّهِمْ لَا نُفَرِّ‌قُ بَيْنَ أَحَدٍ مِّنْهُمْ وَنَحْنُ لَهُ مُسْلِمُونَ

"Say (O Muslims): We believe in Allah and that which is revealed unto us and that which was revealed unto Abraham, and Ishmael, and Isaac, and Jacob, and the tribes, and that which Moses and Jesus received, and that which the prophets received from their Lord. We make no distinction between any of them, and unto Him we have surrendered."

Quran 2:285
آمَنَ الرَّ‌سُولُ بِمَا أُنزِلَ إِلَيْهِ مِن رَّ‌بِّهِ وَالْمُؤْمِنُونَ ۚ كُلٌّ آمَنَ بِاللَّـهِ وَمَلَائِكَتِهِ وَكُتُبِهِ وَرُ‌سُلِهِ لَا نُفَرِّ‌قُ بَيْنَ أَحَدٍ مِّن رُّ‌سُلِهِ

"The Messenger has believed in what was revealed to him from his Lord, and [so have] the believers. All of them have believed in Allah and His angels and His books and His messengers, [saying], "We make no distinction between any of His messengers."

Even though there's no doubt about the position of Muhammad صلى الله عليه وسلم, we muslims don't like to engage in this kind of popularity contest between messengers. He himself didn't like it:

Once while a Jew was selling something, he was offered a price that he was not pleased with. So, he said:
"No, by Him Who gave Moses superiority over all human beings!"
Hearing him, an Ansari man got up and slapped him on the face and said:
"You say: By Him Who Gave Moses superiority over all human beings although the Prophet (Muhammad) is present amongst us!"
The Jew went to the Prophet and said:
"O Abu al Qasim! I am under the assurance and contract of security, so what right does so-and-so have to slap me?"
The Prophet asked the other:
"Why have you slapped?".
He told him the whole story. The Prophet became angry, till anger appeared on his face, and said:
"Don't give superiority to any prophet amongst Allah's Prophets, for when the trumpet will be blown, everyone on the earth and in the heavens will become unconscious except those whom Allah will exempt. The trumpet will be blown for the second time and I will be the first to be resurrected to see Moses holding Allah's Throne. I will not know whether the unconsciousness which Moses received on the Day of Tur has been sufficient for him, or has he got up before me. And I do not say that there is anybody who is better than Yunus bin Matta." (Sahih Bukhari)

"The Seal of the Prophets" means that he is the final prophet.

This is from a Hadith (Saying of the Prophet).

Trying to understand. Thanks for your patience. So the Qur'an says Allah says Muhammad was a sinner (47.19), and you don't refute that. But Ibn Hibbaan says that Muhammad said Isa was also a sinner, even though the Qur'an calls Isa holy in 19.19 and the New Testament says he never sinned. Am I getting it?