Everything in the universe testifies that Islam is a true religion
4-8-2008 | IslamWeb
Question:
I had a debate with a Christian man and he asked me ‘why are you a Muslim?’, and ‘what did you gain from Islam?’
Please give me a decisive and convincing answer.
Answer:
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, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
A Muslim’s belief in his religion must be from a complete rational conviction that cannot be subjected to doubt, because Islam is not simply a blind imitation like the case of some religions which says to its followers: ‘close your eyes and follow me’. Indeed Islam gave its followers the tranquillity of the heart, inner peace, and a rational conviction that it is the true religion from Allaah which falsehood cannot approach from before it or from behind it.
The Muslims are convinced and content with their religion because of the following:
1- It is the religion of Allaah to which all the Prophets of Allaah successively called, starting from the father of humanity –Prophet Aadam 
–all the way until the last Prophet, Muhammad 
. This was after the human mind became mature from the succession of Prophets who were sent to the people with the same call.
2- This great religion corresponds to the Fitrah (natural disposition upon which Allaah created mankind) of the human being. Islam fulfils both man’s intellectual and material needs. This religion also harmonizes with his mind in regard to his belief, acts of worship, morals, dealings, and rulings in every field.
3- This religion only brings what can be conceived and accepted by the sane mind. It [religion] never brings something that is judged by the mind to be impossible to achieve, contrarily to other religions which are full of falsehood, superstitions, illusions and nonsense.
It is for this reason that the belief of a Muslim increases day after day. The more science advancements are made and new inventions and discoveries are found, the stronger a Muslim becomes in his belief in this great religion. The totality of scientific discoveries confirm the validity and authenticity of Islam; Allaah Says (what means): {We will show them Our signs in the horizons and within themselves until it becomes clear to them that it (the Quran) is the truth.}[Quran 41:53]
For more benefit, please refer to Fatwa 91019.
Allaah further Says (what means): {And We have sent down to you the Book as clarification for all things and as guidance and mercy and good tidings for the Muslims.}[Quran 16:89]
Therefore, everything in this universe around us makes a Muslim proudly proclaim ‘I am a Muslim’, because everything in this universe testifies to the greatness and truthfulness of Islam.
For more benefit on the merits of Islam, please refer to Fataawa (plural of Fatwa) 85456 and 102075, and Fataawa 81929, 86091 and 82057 on the comprehensiveness of the religion of Islam, and to Fataawa 81979, 88906 and 88051 that Islam is the religion of all the Prophets, may Allaah exalt their mention, to Fataawa 88176 and 85234 that Islam is from Allaah.
Allaah Knows best.