Why do people believe in Muhammad when he killed to spread his religion and in Allaah when science shows that the only God is nature taking its course? It seems to me that this was a grand scheme to make himself (Muhammad) powerful.
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
First of all, we welcome you in our site and we hope that this will not be your last visit. We are ready to answer any question that you might have.
As regards your question why people believed in Muhammad (), the answer is that they believed in him because of the evidences that proved that he was truly a Prophet and because of the miracles with which Allaah supported him. The best of which is the Quran, which is a miracle in its wording and text, eloquence, meaning, and structure. It relates the news of the unseen and the hidden matters of the upper world and lower world, and scientific issues which modern science is gradually discovering day by day. There are other miracles which appear to us day by day. We are sure that if you read the translation of the meaning of the Quran without prejudice while sincerely seeking the truth, you will discover, Allaah willing, that it is Allaah Who created the universe and He is the Lord of mankind, Jinn and all that exists and that Muhammad is a true messenger from Allaah. Try and you will find out.
Furthermore, among the reasons that made people believe in Muhammad is the greatness of this religion which was sent to him; a just and fair religion which corresponds to sound mind and sound reason. Moreover, the Prophet had noble and great characters, he was truthful and never lied to an extent that his people used to call him 'The Trustworthy', he was courageous, generous, just, caring for others, kind and affectionate, and he had other good characteristics and noble manners which can only be found in a Prophet. All of these were reasons why people believed in him and believed in what he was sent with.
With regard to your statement that Muhammad killed people to spread religion, the answer is that you are frankly not aware of history. Indeed the people, who believed in him and embraced the religion of Allaah, did so by their own will and desire, and they are the overwhelming majority of Muslims, they believed because of the reasons that we have already mentioned. Until the present day, groups of people embrace Islam without war in the country where you live just because they found out that it is the true religion which Allaah chose for His slaves. If you refer to the statistics which show the number of people who embrace Islam in your country, you will find out.
The people whom the Prophet fought against are those who stood in his way, obstructing his call and preventing him from spreading good, guidance and the truth to the people, and in order to save them from the punishment of this world and the torment of the Hereafter. There is no doubt that whoever obstructs the truth and prevents people from discovering it and following it in order to save themselves, he deserves to be fought against if is not possible to get rid of such person except by fighting him.
Concerning your statement that people do not believe in Allaah because modern science prove that nature is the only creator, this also proves that you are not aware of modern science. Indeed modern science proves that this nature had not existed before and that it was created by a Great and Powerful Creator. In this regard please refer to Fatwa 81529.
Finally, sound mind proves that this nature is either created by a Creator or that it is created by itself. If a person denies that it is created by a Creator then this implies that he should deny that it is created by itself as this is even more impossible. May Allaah guide you to the Truth.
Allaah Knows best.
You can search for fatwa through many choices