God tolerates our evil actions to give us a chance to repent. God could have stopped the hand of Cain when he killed Abel. That was the first murder on earth, but God wants us to truly want good on earth as it is in Heaven. For that we have to be proactive in bringing about good.
We often forget who we are in relation to God. We are His servants. He has given us the task of keeping the earth and ourselves for Him. Does a master do his servants work and then pay him for it? People expect God to do everything for them and still they expect to receive the reward of eternal life. If we are called to live like the angels then we have to do like they do, obey God’s commands and bring about good.
If God had not given us His commands, we would not know what is good or bad, so we who are servants of God, cannot judge God for the wrongs we see. Scripture says, God cannot deceive nor is He deceived. He does not cause anyone to sin.
To say that God should stop evil is like saying why does a baby have to breath on its own once it is out of the womb, the mother knows it will dies without breathing, so she should continue breathing for the child and not sever the umbilical chord. The fact is that the child is quite capable of breathing on its own after birth.
God has given us His Holy Spirit. We have the very presence of God in our souls through our baptism. We have to choose to listen to Him and work towards building good and destroying evil. As the scripture says, God’s ways are not mans ways, so we need to look at this from how we can do God’s will and not try to judge God who is all good and just.