From an Islamic perspective, there is absolutely no compulsion on people to embrace it. People have always entered Islam willingly. The historical presence of non-Muslim minorities living among Muslims is evidence of tolerance in Islam.
Islam spread in the most populated Muslim countries: Indonesia, Malaysia, Pakistan, Bangladesh, and within Africa through contact between the natives and Muslim travellers and merchants, who brought with them not only goods, but also Islamic values such as straight dealing, honesty and generosity.
The impact of Muslims upon these communities was tremendous. In Singapore, near the port where the Arab traders used to land, the residents say that the natives used to prefer to buy from Muslim merchants because they expected good treatment and fair prices.
As was the case in most of the areas to which Islam spread, peaceful and voluntary reversion was far more important than conquest and force in spreading the faith in Southeast Asia. Almost everywhere in the islands of the region, trading contacts paved the way for reversion. Muslim merchants and sailors introduced local peoples to the ideas and rituals of the new faith and impressed on them how much of the known world had already been reverted. The first areas to be won to Islam in the last decades of the 13th century were several small port centres on the northern coast of Sumatra. From these ports, the religion spread in the following centuries across the Strait of Malacca to Malaya.
It is unfair to compare the spread of Islam in Asia and Africa with the spread of Islam in the West, and blame Muslims for not effectively promoting their religion in the West. Unlike the modern western world, the Asians' and Africans' history was free from hostility and enmity against Muslims, and therefore, their reversion to Islam was natural and easy.
Could Da'wah Fail?
Allah will guide, through Da'wah (Islamic propagation), those who are worthy and qualified for His Mercy; those who have good hearts and are sincerely searching for the truth. He will turn away from it those who do not deserve His mercy; those who chose to divert from His way. This is decreed according to His perfect Wisdom and Knowledge.
The success of Da'wah is guaranteed as a fulfilment of Allah’s promises; He Says (what means): “… And who is more truthful than Allah…” [Quran: 4:87]
1. Allah promised to make the way for Da'wah easy for Prophet Muhammad salallaahu 'alayhi wa sallam, and his followers alike; He Says (what means): “And We will ease you toward ease.” [Quran: 87:8]
2. Allah also promised to preserve the Quran, His last guidance to mankind. It is forever protected from any sort of distortion, change, or modification; He Says (what means): “Indeed, it is We who sent down the message [i.e., the Quran], and indeed, We will be its guardian.” [Quran: 15:9]
3. Allah promised to make Da'wah prevail and reach every place on earth, so that all mankind will be aware that Islam is the truth from their Lord; He Says (what means): “We will show them Our signs in the horizons and within themselves until it becomes clear to them that it is the truth...” [Quran: 41:53]
4.Prophet Muhammad assured us that Islam is the religion of the future and will spread all over the world when he said: “Indeed, Islam will reach every place that the day and night reach. There is no house (in city or desert) on the Earth except that Islam will enter it.” [Ahmad]
Due to all of these reasons, Da'wah can never fail; that is why Prophet Muhammad expected his followers to outnumber the followers of other prophets; He said: “All of the prophets before me were given (tangible) miracles, due to which, people believed in them. But the miracle that has been given to me is indeed a revelation that Allah revealed to me [i.e., Quran and Sunnah]. So I hope, on the Day of Judgement, my followers will outnumber the followers of other prophets.” [Al-Bukhari]
In order for Da'wah to be effective, the caller must have sincere intention and, above all, a strong sense of piety. In order to share Islam with people, we must develop strong relationships within our Ummah (Muslim community) to support these efforts with Da'wah centres and well-written material. Each of us has a gift from Allah and we should not ignore our obligation in fear of rejection or failure, but join together to contribute our talents and resources to share the gift of Islam.