S3. Why does the Qur'an say "..And those who are Jews, and Sabaeans, and Christians, and whosoever believeth in Allah (will go to heaven)"; but then says "If anyone desires a religion other than Islam, never will it be accepted of him"?

OK! nice question

first we have to agree in a definetion of islam

Islam mean submition to the one god (Allah)

Muslim doesn't mean People of Mohammed only .. but in quran it's said all prophet are muslims and also god said in quran Abraham called you Muslims before...etc.

"..And those who are Jews, and Sabaeans, and Christians, and whosoever believeth in Allah (will go to heaven)";

Yes.. the true chrestian would go to the heaven
the true Jews who Obey God and prophets will go to the heaven.
.....etc.

if they obey the true bath as they prophets (Moses, Jesus..etc.) ask them to do ... they would be Muslims

but after the messege of Mohammed pbuh .. every should belive in him and other prophets as well and being a muslim

5:44-48 ((Verily, We did send down the Taurat (Torah) [to Musa (Moses)], therein was guidance and light..And in their footsteps, We sent 'Iesa (Jesus), son of Maryam (Mary), confirming the Taurat (Torah) that had come before him, and We gave him the Injeel (Gospel), in which was guidance and light ....And We have sent down to you (O Muhammad SAW) the Book (this Quran) in truth, confirming the Scripture that came before it and trustworthy in highness and a witness) over it (old Scriptures). ))

here you can see the mening of Islam in next verse

3:52((Then when 'Iesa (Jesus) came to know of their disbelief, he said: "Who will be my helpers in Allah's Cause?" Al-Hawariun (the disciples) said: "We are the helpers of Allah; we believe in Allah, and bear witness that we are Muslims (i.e. we submit to Allah)." ))

so Islam mean to submit to god and worshiping the one God alone.

i hope it's clear now

Hi. I asked this question not for rude answers, but as a serious inquiry to Muslims. If youre just going to be a smart@$$ and have nothing productive to say, than please don't Answer :)

Sounds to me like the Qur'an makes as much sense as the Bible - no doubt written by the same people or last some that knew each other