I became an atheist for a year over this very thought that life is not fair so there can't be a God. I think you have to consider the beatitudes, which explain that those that suffer in this life are actually blessed.
Matthew 5:1-12English Standard Version (ESV)
The Sermon on the Mount
5 Seeing the crowds, he went up on the mountain, and when he sat down, his disciples came to him.
The Beatitudes
2 And he opened his mouth and taught them, saying:
3 Blessed are the poor in spirit, for theirs is the kingdom of heaven.
4 Blessed are those who mourn, for they shall be comforted.
5 Blessed are the meek, for they shall inherit the earth.
6 Blessed are those who hunger and thirst for righteousness, for they shall be satisfied.
7 Blessed are the merciful, for they shall receive mercy.
8 Blessed are the pure in heart, for they shall see God.
9 Blessed are the peacemakers, for they shall be called sons[
a] of God.
10 Blessed are those who are persecuted for righteousness' sake, for theirs is the kingdom of heaven.
11 Blessed are you when others revile you and persecute you and utter all kinds of evil against you falsely on my account. 12 Rejoice and be glad, for your reward is great in heaven, for so they persecuted the prophets who were before you.
I also think that life is not fair, so that we have work to do for God, like creating heaven on earth, spreading the gospel, feeding the orphans, getting justice for widows, etc..
Isaiah 1:16-18
16Wash yourselves; make yourselves clean;
remove the evil of your deeds from before my eyes;
cease to do evil,
17 learn to do good;
seek justice,
correct oppression;
bring justice to the fatherless,
plead the widows cause.
18Come now, let us reason
c together, says the Lord:
though your sins are like scarlet,
they shall be as white as snow;
though they are red like crimson,
they shall become like wool.
That aside, all will be made fair at Judgment Day.
Acts 17:31
English Standard Version
because he has fixed a day on which he will judge the world in righteousness by a man whom he has appointed; and of this he has given assurance to all by raising him from the dead.