People with materialistic beliefs are often overwhelmed by doubt when they see evil-doers prosper and live long lives, while those trying to stay true to their conscience are often taken by the Lord at an early age? The parable of weeds among the wheat (see: Matthew 13: 24-30) explains this situation well.
Sometimes it is very difficult to distinguish the weeds from the wheat because they look similar. It is also true that a person can improve in his lifetime. The Lord is long-suffering and hopes for a person to correct his ways until He sees that this person is incorrigible. Only then the Lord calls him to His judgement. On the other hand, sometimes a person is ready for the Kingdom of God, and the Lord calls him before his state of mind worsens.
Very often people live to an old age before they come to know God, repenting and correcting their inner state. Of course, they cannot change their past, but they do revise their lives in many ways. Their repentant sighs matter to God and accompany their souls on the way to salvation until, when a person is ready, the Lord calls him to enter into His eternal joy.
There is therefore no need to be perplexed and lament about God being unjust. Quite on the contrary, He is ever so just and very merciful, wanting salvation for everyone. The Lord saves those who are ready, giving those who aren’t an opportunity to be saved. The fact that we are still alive means that the Lord gives us a chance for salvation.
Translated by The Catalogue of Good Deeds