إِلَّا الَّذِينَ آمَنُوا وَعَمِلُوا الصَّالِحَاتِ
Except those who believe and do righteous deeds.
The exception in 103:3 qualifies the general proposition of the previous verse. Illā is therefore a decisive logical and rhetorical turning point.
Faith and righteous action are conjoined, and two further mutual exhortations follow. The passage presents a composite description, not a one-condition summary.