Looking all around us, it’s clear that there’s a Creator of everything. If we found a Mercedes Benz in the middle of the dessert, would we think it was created from sand and million of years of evolution? Through this evolution it developed seat belts, the ability to run on petrol or be electrically charged and so on? No, reasonable person would believe this.
Now the human body with all its complexity, a heart that beats without thought even while we’re sleeping, white blood cells to fight off infection, blood that thickens so that when we get a cut we don’t bleed out every time and so on. Are all these thoughtful features really just a product of randomness? If that’s the case, that humans are randomly developing new features, then there should be different humans with wildly different features. Yet there’s no humans with horns, or others with 5 eyes rather than 2 and so on. Did all our genes randomly decide to agree on what random features they would develop and what random features they would ignore?
So it becomes evident that rather than randomness (does randomness even exist?) deciding things, it makes more sense that a great powerful and intelligent Creator is.
Next this Creator sent many prophets and messengers. Just like how we expect a manual with every complex product we buy, so we can know the dos and don’ts of using that product, Allah sent us books telling us the dos and don’ts for mankind. The final book being the Quran, and the final Prophet being Muhammad (peace and blessings be upon him). As this is the final book for mankind, it must be preserved without error, which the Quran itself challenges the reader to find.
أَفَلَا يَتَدَبَّرُونَ الْقُرْآنَ ۚ وَلَوْ كَانَ مِنْ عِندِ غَيْرِ اللَّـهِ لَوَجَدُوا فِيهِ اخْتِلَافًا كَثِيرًاQuran [4:82]
Then do they not reflect upon the Qur’an? If it had been from [any] other than Allah, they would have found within it much contradiction.
The Quran talks about many things that a illiterate Arab could not possibly know, such as the Mountains being like pegs holding the earth firm, every living thing being created from water, the atmosphere of earth protecting us from dangerous rays and meteorites and much more. Read more about that here:
Finally Islam is the only religion that teaches the pure monotheism of worshipping the Creator alone. We don’t say the Creator is a man, woman, monkey, zebra, spirit and so on. There is nothing like the Creator. Anything we imagine is not the Creator. The Creator is alone in his Lordship. He has no one and no thing that He needs. No son, no daughter, no mother, no father, no wife, no friend. The Creator is alone in His dominion.
This great Creator is the only thing deserving of worship. Everything else is weak by comparison. The richest most powerful man, can’t bring life to the dead. He can’t know the future. He can’t live forever without growing weak. He can’t even guarantee he’ll live to the next day.
So if you believe in a great Creator, who sent Prophets and Messengers to mankind, including Moses, Jesus and Muhammad, peace and blessings be upon all of them, to worship the Creator alone and follow His Prophets, then you’re a Muslim. A Muslim is one who submits his will to the Creator. What follows is simply testifying to this truth and then one day at a time trying your best to follow the obligations of being a Muslim. Such as praying, fasting, giving in charity to the poor and needy, being kind to parents, not stealing not cheating not lying and so on.
The testimony is easy to say. In English it’s:
I bear witness, that there’s nothing deserving of worship except Allah (the Creator), and that Prophet Muhammad (Peace and blessings be upon him) is Allah’s servant and Messenger.
Ash-hadu, an laa, ilaaha illa Allah, wa ash-hadu, an-na muhammadan abdu-hu, wa rasooluhu.