the believers are only the ones who have believed in allah and his messenger and then doubt not but strive with their properties and their lives in the cause of allah. it is those who are the truthful.
إنما المؤمنون الذين آمنوا بالله ورسوله ثم لم يرتابوا وجاهدوا بأموالهم وأنفسهم في سبيل الله أولئك هم الصادقون