The true believers that is those who are true in their affirmation of faith — as He makes explicit in what follows — are only those who believe in God and His Messenger and then have not doubted they have not been uncertain of their faith and who strive with their wealth and their souls for the cause of God hence their striving manifests the sincerity of their faith. It is they who are sincere in their faith not those who say ‘We believe’ and from whom all that has been forthcoming is their submission to the religion.
