That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust. (Matt. 5:45)
“None of the righteous has obtained a reward quickly, but waits for it; for if God should pay the recompense of the righteous speedily, we should immediately be training ourselves in commerce and not in godliness; for we should seem to be righteous when we were pursuing not piety but gain.” (II Clement XX, 3, 4.)
Is it not true of the wicked also? Were the wicked to be immediately punished for their deeds, then they would learn to be righteous, not for the sake of righteousness itself; rather to avoid the immediate punishment, thus losing our free will.
“But because man is possessed of free will from the beginning, and God is possessed of free will, in whose likeness man was created, advice is always given to him to keep fast the good, which thing is done by obedience to God.” (Irenaeus, Against Heresies, IV, 4.)
“God has always preserved freedom, and the power of self-government in man, while at the same time He issued His own exhortations, in order that those who do not obey Him should be righteously judged because they have not obeyed Him; and that those who obeyed and believed on Him should be honoured in immortality.” (Irenaeus, Against Heresies, IV, 15,2.)
“The commandments given to man may be viewed as questions because man is free. I obey not because I must but because I will. The Lord wants me, even me, to be his companion. ‘Can two walk together, except they be agreed?’ (Amos 3:3.) As I hearken and obey, as I quickly respond, I show my desire to be in agreement with Him.” (Rasmussen, Dennis, The Lord’s Question, 7.)
If God were to reward or punish immediately, there would be no room for development; and after all, is that not why were are here in the first place?