Surah Al-Hujurat, ayah 15

49:15

إِنَّمَا ٱلۡمُؤۡمِنُونَ ٱلَّذِينَ ءَامَنُواْ بِٱللَّهِ وَرَسُولِهِۦ ثُمَّ لَمۡ يَرۡتَابُواْ وَجَٰهَدُواْ بِأَمۡوَٰلِهِمۡ وَأَنفُسِهِمۡ فِي سَبِيلِ ٱللَّهِۚ أُوْلَٰٓئِكَ هُمُ ٱلصَّٰدِقُونَ ١٥

Innamal-mu'minūnal-ladhīna āmanū billāhi warasūlihī thumma lam yartābū wajāhadū bi amwālihim wa anfusihim fī sabīlillāhi ulā'ika humus-sādiqūn

The believers are only the ones who have believed in Allāh and His Messenger and then doubt not but strive with their properties and their lives in the cause of Allāh. It is those who are the truthful.