﴿ يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوا۟ ٱتَّقُوا۟ ٱللَّهَ وَءَامِنُوا۟ بِرَسُولِهِۦ يُؤْتِكُمْ كِفْلَيْنِ مِن رَّحْمَتِهِۦ وَيَجْعَل لَّكُمْ نُورًۭا تَمْشُونَ بِهِۦ وَيَغْفِرْ لَكُمْ ۚ وَٱللَّهُ غَفُورٌۭ رَّحِيمٌۭ ﴾

“O YOU who have attained to faith! Remain con­scious of God, and believe in His Apostle, [and] He will grant you doubly of His grace, and will light for you a light wherein you shall walk, and will forgive you [your past sins]: for God is much-forgiving, a dispenser of grace.”

‘Believers,’ here refer to those who embraced the faith of Jesus. Those who had faith in the previous prophet and now, having discovered the Truth in the call of the Last of the Prophets, adopt his faith, are entitled to a double reward. Similarly, if those who are Muslims by birth study Islam afresh, and with renewed Islamic consciousness, become believers or Muslims, they too will be entitled to a double reward in the eyes of God.