Living The Quran
From Issue: 488 [Read full issue]
Al-Ankabut (The Spider)
Chapter 29: Verse 3 (Partial)
God's Justice
"Allah will most certainly ascertain those who spoke the truth and those who lied."
When one reads this verse, a likely question that arises is: since God knows fully what everyone's conduct will be, what is the point in testing him? The answer is that as long as a person does not commit a certain action, irrespective of his ability to do so, the dictates of justice require that he should neither be rewarded nor punished. One person might be potentially trustworthy and another potentially untrustworthy. However, unless they act in one manner or the other, it is discordant with God's justice to reward or punish them only on the basis of His knowledge of those actions that will take place in the future.
God, no doubt, has knowledge of both the past and the future, yet this does not have a bearing on the manner in which He will dispense justice. He does not punish anyone simply because he is inclined to steal or because he is likely to steal in the future. Rather, His punishment is contingent upon the person actually stealing. By the same token, God does not bestow His rewards on someone just because they will grow into excellent believers or as excellent fighters in God's cause. On the contrary, this person too only earns his reward by dint of his actually having sincere faith and striving in God's cause.
Source:
"Towards Understanding the Quran" - Sayyid Abul Ala Mawdudi, Vol. 8, pp. 7-8