It is the basic belief of Islam that Islam is the way to Heaven, the door to Eternal Paradise, while not accepting Islam is the way to Hell Fire- also eternal. The sufferings in Hell are mentioned in the Quran many times (Chapter 22 Verses 19-22 are a bit too horrific!), and the whole Quran is full of sentences like "For the disbelievers there is a painful doom". There are also Muslims desperate to spread 'The Message of Islam' in India- through leaflets on railway stations, and other things urging Hindus to give up idolatory and polytheism and recognizing Islam as the only true religion of God since 'God will not accept anything other than Islam' (Quran 3:85). Even a cursory visit to the website www.islamreligion.com which is a website made for non-Muslims and massively advertized on the Internet makes this point very clear. Often the question is asked- "What about the people who are unaware of Islam?"
The leaflets and Muslims who try their best to 'spread the message of Islam' say that their job is only to spread the message of Islam- 'there is no compulsion in religion' (Quran 2:256) which is of course, false, since such passages are early Meccan verses when Muhammad's followers were in a minority and they are abrogated by later Medinan verses which are intolerant . As for people who are unaware about Islam, some say "God will judge such people by their deeds and decide whether they will go to Hell or Heaven. As for those who were aware about Islam but did not convert to it, Eternal Hell is the only place where God will send them. As for believers, i.e. Muslims, God will send good people to Heaven directly, evil-doers in Hell for a period of time depending on their deeds and then transfer them to Eternal Heaven because they followed the true religion of God". There are many who believe that all non-Muslims will automatically go to Hell, irrespective of whether they are aware of Islam or not. Not believing in God and Muhammad as his Final Prophet is sufficient crime for Eternal hell, even though they may not have even heard of Muhammad ever. If one assumes that all non-Muslims go to Hell irrespective of whether they are aware of Islam or not, then this leads one to ask- Why would God not even keep some people aware of Islam, give them a chance to accept Muhammad's Prophet-hood and directly burn them in Hell for eternity for no fault of theirs? Even Muslims who write letters to the editor in English weekly Organiser, which is run by RSS activists, have written that "Message of Islam has not reached India". This was written by Tanvir Fatima in one her letters.
Now the question comes- "Would the Almighty God leave 80 % people in the world unaware of the Message of his own true religion?" Islam has been present in India since more than 1300 years, the first attack was in AD 636 and the first mosque was built in Kerala in 629 AD, during Muhammad's own lifetime. Even after so many years in India, ruling considerable part of the country for more than 500 years (AD 1206-1707), how has the message of Islam not reached the Indian people? Most Indians, even today in this age of Internet, are totally unaware about the basic ideologies of Islam, its strong hatred for idolatry, its belief in an exclusive, jealous God, its belief in Eternal Heaven and Hell and Day of Judgment, or its massive adulation and following of Muhammad etc. As an example, let us say breaking of idols. Since Islam considers idolatry as an unforgivable sin (believing that worshiping God in the form of an idol or symbol is equal to worshiping someone other than God, and this makes the exclusive God jealous) it would rejoice at breaking of idols of Tulja Bhavani (of whom Chhatrapati Shivaji was a great devotee) in her sacred city of Tuljapur. But Hindus- then at the time of Shivaji as well as now-would consider this as a big sin, as an insult of Goddess Bhavani and genuinely believe that idol breakers would be punished by God for such an act. If this is the situation in a place like India, where Islam has been present for more than 1300 years, then what can be said about places where Islam did not even touch until recently, like South America, or Australia/ New Zealand?
As in 1991 AD, Muslims constituted 19.9 % of the world population. This percentage has grown tremendously with time, especially in the past 100 years,and even more since the holocaust and genocide and elimination of virtually all Hindus from Pakistan (from 20 % in 1947 to 1 % now) and Bangladesh (29 % in 1947 to less than 10 % now). This global Muslim population must have been something like 15 % till a 100 years ago and even lesser and lesser as we go back in time. Now out of the remaining 85 % non-Muslims of the world, most of them were unaware of the Message of Islam, its ideology and beliefs! And a majority were not even aware about Islam's existence! Poor, illiterate people of South America, or North America's original residents till, say, at least AD 1800 (more than a thousand years since Islam's birth), were not even aware about existence of any such religion in any part of the world! Even today, only a little more than 20 % of the world is Muslim and most of the remaining non-Muslims are unaware about Islam's message and ideologies.
If Islam was really from God, would he have kept an overwhelming majority of the humans unaware about his only true religion? He, being all-powerful, all-knowing could have easily found a way to make South Americans and North Americans and the rest of the world aware about Islam and its message right since the beginning of Islam. He could have also easily aided Muslims in spreading Islam's message to these places, and helped them discover these places in the first place, instead of allowing Christopher Columbus to accidentally discover America in 1492, nearly 900 years after the birth of Islam! That even after nearly 1400 years after its birth, and massive killings in wars, enslaving people, forcibly converting the entire populations to Islam (Islamic scripture itself is quite unambiguous about the manner in which Islam was forced on the people by Muhammad and his supporters) -regions North and West of Arabia succumbed immediately after Muhammad's death, areas like Turkey were subdued in AD 960- only little more than 20 % of the world follows Islam, shows that it is definitely not from God. If God willed and Islam was truly his religion, he would have easily made everyone aware about Islam and its ideologies in the present form (i.e. the Quran containing so many errors and contradictions). The word 'present form' is used because doing supernatural things to prove Islam's truth such as rearranging stars to make them read "Islam is true- it is from God and I have rearranged stars to make you aware of it" or to order Angel Gabriel to show himself to everyone today- is not being mentioned at all! To this many Muslims would argue, that God 'tests' Muslims to do their duty and spread his message. Such an argument too could have a little merit had there been at least 20 % followers of God's true religion everywhere in the world -to spread the message of Islam in places like South America and North America throughout Islam's 1400 years. But the Americas remained unknown to the world till almost 900 years after Islam's birth!
In all places where Islam's message has spread, through sword or through preaching, it has been entirely due to humans and it has reached a mere 20 % of the world in 1400 years.