Al-Baqarah - 2:135

وَقَالُواْ كُونُواْ هُودًا أَوْ نَصَارَى تَهْتَدُواْ قُلْ بَلْ مِلَّةَ إِبْرَاهِيمَ حَنِيفًا وَمَا كَانَ مِنَ الْمُشْرِكِينَ
[2:135]
And they say: Be Jews or Christians, you will be on the right course. Say: Nay! (we follow) the religion of Ibrahim, the Hanif, and he was not one of the polytheists.
They say: "Become Jews or Christians if ye would be guided (To salvation)." Say thou: "Nay! (I would rather) the Religion of Abraham the True, and he joined not gods with Allah."
And they say: Be Jews or Christians, then ye will be rightly guided. Say (unto them, O Muhammad): Nay, but (we follow) the religion of Abraham, the upright, and he was not of the idolaters.