Back 
Surah 3. Aal-Imran
Ayah 19 - 20
19 إِنَّ ٱلدِّينَ عِندَ ٱللَّهِ ٱلْإِسْلَـٰمُ ۗ وَمَا ٱخْتَلَفَ ٱلَّذِينَ أُوتُوا۟ ٱلْكِتَـٰبَ إِلَّا مِنۢ بَعْدِ مَا جَآءَهُمُ ٱلْعِلْمُ بَغْيًۢا بَيْنَهُمْ ۗ وَمَن يَكْفُرْ بِـَٔايَـٰتِ ٱللَّهِ فَإِنَّ ٱللَّهَ سَرِيعُ ٱلْحِسَابِ
20 فَإِنْ حَآجُّوكَ فَقُلْ أَسْلَمْتُ وَجْهِىَ لِلَّهِ وَمَنِ ٱتَّبَعَنِ ۗ وَقُل لِّلَّذِينَ أُوتُوا۟ ٱلْكِتَـٰبَ وَٱلْأُمِّيِّـۧنَ ءَأَسْلَمْتُمْ ۚ فَإِنْ أَسْلَمُوا۟ فَقَدِ ٱهْتَدَوا۟ ۖ وَّإِن تَوَلَّوْا۟ فَإِنَّمَا عَلَيْكَ ٱلْبَلَـٰغُ ۗ وَٱللَّهُ بَصِيرٌۢ بِٱلْعِبَادِ
[19-20] Indeed, Islam is the only right way of life in the sight of Allah.16 Those who were given the Book, had adopted ways different from this Way for no other reason than to enable themselves to behave unjustly towards one another, after knowledge .had come to them;17 they should know that Allah is very prompt at reckoning with those who deny and reject His Commandments and Guidance. Now, if they dispute with you, tell them, "As for me and my followers, we have surrendered to Allah." Then ask those, who possess the Book and those who do not, "Have you also surrendered to Him"?18 If they have surrendered, they are rightly guided. But if they turn away (you need not worry), for your sole responsibility was to convey the Message. As to the consequence, Allah Himself watches closely what His servants do.
16It implies that in the sight of Allah there is only one correct system and one right way of life for man. It is this: Man should worship Allah, acknowledge Him as his Master and surrender himself completely to Him in His worship and service. He should not invent his own way of worship but should faithfully follow that Guidance alone which Allah has revealed through His Messengers, without adding anything to or taking away anything from it. This way of thinking and behaving is called "Islam." And it is the absolute right of the Creator and the Master of the Universe that He should not accept as lawful from His subjects, His own creation, any way other than Islam. One might ignorantly think it to be one's right to follow any system, atheism, idolatry, etc., but the Ruler of the Universe will regard this behaviour as rebellious.
17It means that originally Islam and Islam alone was professed and preached by every Messenger who was sent by Allah at any time in any comer of the world. Hence any Scripture sent down to any community in any language taught the same Islam. Afterwards, the people distorted this original religion and added to it something to suit their interests or to gratify their lusts, and omitted those things from it which went against their interests. They invented new religions just because they wanted to transgress the prescribed limits and run after undue privileges and gains and distinctions. Thus they made changes in the beliefs, principles and injunctions of the true Faith to make it subservient to their own desires and lusts.
18The same thing may be expressed thus: "My followers and I have been convinced of this same pure Islam and have accepted the true religion of Allah; now tell us whether you also will give up the innovations which you and your elders have introduced into it and turn to the original true religion."