We don't know God’s plan - evil might have a higher purpose
God, in their omniscience, knows the outcome of everything. It is possible that they permit some evil acts because to prevent them would incur greater evil or prevent greater good.
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God, in their omniscience, understands the impact and outcomes of their actions. Therefore, it is plausible that they have a plan we do not understand or already act to eliminate evil when they are able to do so without incurring a greater evil or preventing the occurrence of a greater good.
Although many forms of theodicy have been proposed, some Christian thinkers have rejected as impious any attempt to fathom God’s purposes or to judge God’s actions by human standards. Some believe that God ordained for evil to exist so that it would bring Him glory. Others argue that an all-powerful, all-good God can allow evil in order to obtain the greater, eternal good. An omniscient and omnipotent God can intervene to prevent evil from occurring. However, they are unlikely to do so if the outcome of the divine intervention would prevent the occurrence of a greater good or cause a greater evil.  God uses evil as a divine tool. God has a plan. Once he has realised his plan, he will eliminate evil. Christians believe that all wrongs—every single one—will face a day of reckoning one day. They believe that God is acting to restrain evil now, just as He has in the past. The Bible makes it clear that the struggles we experience now are not the purpose for which we exist, nor do they define our value. Instead, there is a point to the suffering and a plan that involves making all wrongs right. 
The theory is incomplete because it cannot explain how an action attributes a greater or lesser value to evil deeds. Does God decide when and when not to eliminate evil with the end goal of creating the best possible world for all people? Or does God decide when to intervene based on making preventing many ills on falling on one person and making their life miserable? Does God decide how and when to intervene based on what is morally right and morally wrong? For example, if instead of becoming a serial killer, the child grows up to be a morally impeccable person but accidentally kills four people in a car accident. Would it not be the morally correct decision to spare the child from leukaemia, even if it results in the death of four other people? For the argument to be effective, it must incorporate a bridge between good and evil, and morally right and wrong actions. 
[P1] God is all-good, all-knowing, and all-powerful. [P2] Therefore, the only evil he would permit would be that which the act of preventing would prompt greater evil or prevent greater good. [P3] Therefore, evil on earth is compatible with an omniscient, omnipotent, benevolent God.
Rejecting the premises
[Rejecting P2] There is no objective way of assessing what would be a "greater" evil.