The best of you before Islam are the best of you in Islam
from Messenger of Allah ﷺ said, "You find that people are ˹like˺ minerals (hidden gems): those who were the best in the pre-Islamic period, are also the best in Islam, if they have ˹deep˺ understanding. You see that the best amongst the people in this respect (in positions of authority/leadership) are those who hate it most. And you see that the worst among the people is the two-faced ˹person˺ who appears to these with one face and others with another face."
عَنْ رَسُولِ اللَّهِ ﷺ قَالَ «تَجِدُونَ النَّاسَ مَعَادِنَ خِيَارُهُمْ فِي الْجَاهِلِيَّةِ، خِيَارُهُمْ فِي الإِسْلاَمِ إِذَا فَقِهُوا؛ وَتَجِدُونَ خَيْرَ النَّاسِ فِي هَذَا الشَّأْنِ أَشَدَّهُمْ لَهُ كَرَاهِيَةً؛ وَتَجِدُونَ شَرَّ النَّاسِ ذَا الْوَجْهَيْنِ الَّذِي يَأْتِي هَؤُلاَءِ بِوَجْهٍ وَيَأْتِي هَؤُلاَءِ بِوَجْهٍ۔»