Surat Al Baqarah (111-112)

{ وَقَالُواْ لَن يَدْخُلَ الْجَنَّةَ إِلاَّ مَن كَانَ هُوداً أَوْ نَصَارَى تِلْكَ أَمَانِيُّهُمْ قُلْ هَاتُواْ بُرْهَانَكُمْ إِن كُنتُمْ صَادِقِينَ } [البقرة:  111]

111- The Jews and the Christians were arrogant when they thought that they were alone on the straight path. Each group of them said: None shall enter Paradise except a Jew or a Christian. It was their wish but without right and a claim with no proof. So, tell them, O Messenger: What is your proof to that? Mention one if you are truthful of what you claim.

بَلَى مَنْ أَسْلَمَ وَجْهَهُ لِلّهِ وَهُوَ مُحْسِنٌ فَلَهُ أَجْرُهُ عِندَ رَبِّهِ وَلاَ خَوْفٌ عَلَيْهِمْ وَلاَ هُمْ يَحْزَنُونَ } [البقرة:  112]

112- The general rule is: He who submits himself to Allah in obedience, follows the Sunnah of the Prophet (peace be upon him) and does good deeds in sincerity, his reward is guaranteed by Allah, so he should not fear the future or be sad on what he has left behind. Allah used the word "turned his face to Allah" because it is the most honorable organ, the utensils of feelings, the prostration position (in Salah) and the position where the traces of submission are obvious which is one of the signs of sincerity as Abu As-Su`ud said in his Tafsir.