(Ankabooth ) 29 : 7
وَالَّذِينَ آمَنُوا وَعَمِلُوا الصَّالِحَاتِ لَنُكَفِّرَنَّ عَنْهُمْ سَيِّئَاتِهِمْ وَلَنَجْزِيَنَّهُمْ أَحْسَنَ الَّذِي كَانُوا يَعْمَلُونَ
And those who believed and did righteous deeds, We will surely remove from them their evil deeds and will surely reward them according to the best of what they used to do.
The Best of deeds is to help Lord by propagating Adhikr into entire worlds irrespective of nation or religion. See explanation 16: 97 and 25: 68-70.