Tafsir of Al-Ma'aarij 70:26

The intended meaning of believing in it is affirmation through deeds, as they exhaust themselves in physical acts of obedience, aspiring for the reward of the hereafter. This is because heart-felt belief is common to all Muslims, in which no one has an advantage over another. The use of the present tense verb indicates that this affirmation and these deeds are renewed by them moment after moment.