For the evangelical who employs the free will theodicy (theology of evil), explaining natural disasters is a most difficult theological challenge. The free will theodicy explains evil's existence through the Fall of humanity described in Gen 3 when Adam and Eve ate of the fruit of the tree of the knowledge of good and evil. This event symbolises human rebellion and the point at which evil began to corrupt God's good earth, and humanity began to die.
The free will answer to the problem of evil generally argues that death, chaos and destruction affected God's good creation at the Fall. Before the Fall, there is evil present in creation in the form of the snake (Satan symbolically); however, the snake could not directly affect the creation unless humanity sinned and allowed evil's release.
There are two main ways they argue. First, that there were no natural disasters before the Fall which affected humanity. For the old-earth Christian who holds to an old earth and universe in line with contemporary science, there were likely natural events such as earthquakes, eruptions etc, which God used to help form his world. By the time of the creation of animals the world was in perfect equilibrium without such catastrophic events or with them contained. At the Fall these resumed or were amplified/released and death and destruction ensued. For a young earther, there was no need for these events as God created the world in equilibrium and death, and all destruction, decay, chaos and death resulted from the Fall.
Secondly, you can argue that there were natural disasters before the Fall and these continue until today. There are two main variants here. One is that there were natural events but no death as God preserved his creation. The alternative is that there were natural events which caused animal and other death, but God preserved humanity through them. Another alternative is that the OT accounts should not be taken literally and that natural disasters are part of life and that we cannot be sure of the origin of evil. What matters is not the origin of evil, but that Christ has come into his world to bring hope and to overcome evil ultimately redeeming creation and ending suffering. This new creation can be this world restored – which of course implies that the world did previously exist in equilibrium and will again when Christ returns and all things are sorted. Or, the new creation will be an alternative existence and free of such problems. This implies of course that such a world is possible and so one can then argue, why not this one before evil's chaos took hold?
Contemporary scientifically minded people outside of Christianity and other faith's who rely on the same creation story (Islam, Judaism) struggle to accept any perspective that does not accept that natural catastrophic events have occurred from the inception of the world. They see them as 'normal', part of the world as it is. They argue that the amazing geography of the world and fossil record relies on such events e.g. floods, eruptions, and earthquakes.
Because of this, for us evangelicals this is a point of great challenge in our theological construct no matter how we argue it. I tend to opt for the idea that God created his world with a process that climaxed at a point of equilibrium, something that took a long time (old earth). I am a little torn as to whether death in the animal world was normative but that humans were preserved, or whether death in the animal world did not exist at all before the fall. The latter seems to fit better with the thinking of Paul in Rom 5:12; 8:19-23; the former with what appears evident in scientific enquiry. Currently, I hold the latter in line with what Paul appears to be saying, but am not completely confident of this position. There seem problems with either.
The ancients tended to explain natural disasters in terms of curse and blessing and the peace of the God/gods. If the deity was happy, then there was a cessation of such events. If the deity was displeased for one reason or another, these events would happen. Events such as the Christchurch or Japanese earthquakes were necessarily a message from God, a warning, and some form of repentance or penitence was expected. The Jews thought this of events in the OT period and especially exile, which all pointed to their failure to uphold the covenant and law. Their exile was the ultimate judgment of God, although restoration was also promised. In the Roman world, the same problem occurred, with Romans blaming Christians for natural events, and persecuting them. They destabilised the context and upset the gods (peace of the gods).
Such thinking is common in the Christian world with people interpreting events as God's judgment for sin; often for such things as sexual sins etc (cf. Sodom and Gomorrah). Those Christians who hold to a view that such events happen and that is life in a fallen world, do not blame them directly on sin. Rather, they reflect the problem of a fallen world in general, not direct judgment, but the result of a world fractured and broken. Taking them in this way frees such Christians from having to speak 'prophetically', assuming that they need to find out why something happened, and call for repentance. Rather, they get alongside those suffering knowing that 'sh...t happens' and they grieve with those who grieve and mourn with those who mourn. They do not seek to judge, and blame; rather, they seek to comfort. Hope comes from the presence of the Spirit expressed through love, compassion, care and support. Hope future comes from the return of Christ when the world will be renewed or a new world is created, and never again will the people of God's world suffer from such events. Of course, there is still a call for repentance in the gospel, but the natural events are not directly related to specific sins; rather, it is the general problem of sin from which all humans, Christian alike, must repent.
I strongly prefer the latter point of view. Jesus predicted that such events would occur across his world (esp. Rom 13; cf. Revelation), and does not necessarily link these to direct sin from the nations involved. Rather, it is part of the story of a broken world. Jesus is the key to all this. He came into his fallen world and lived the full experience of being human, frail, weak, and subject to the forces of the world. He was persecuted, suffered, was beaten, and killed, and died. In so doing, he experienced the full brunt of human malice and violence. He also experienced the struggle of living in a broken world, experiencing the forces of the natural world like hurricanes on the lake etc. Whatever the cause of natural events, he is our point of hope, the God who suffered on our behalf for us. He rose from the dead and his Spirit is now released to fill us, not so we can escape into some holy ether above suffering; but to live in it, experiencing it, and yet finding our hope and strength in Jesus and the Spirit, and ultimately in his return. It is about comfort in the midst of suffering, not release from it. This does not rule out miracles where God for his own good purposes intervenes and does something counter-natural. However, the power of death continues to weave its web and the healed fall sick again and eventually die. Death is at work powerfully in God's world. As we live in Christ we experience hope from Christ, in Christ, through Christ, and by his Spirit. Suffering then is real. Suffering is to be expected. We will see more of these events, and no doubt even worse. Some interpret Mark 13 and its parallels in Matt 24; Luke 21 to suggest there will be an increase in intensity in such natural events leading to Christ's return, although others dispute this interpretation. Whatever, hope is greater, dwarfing suffering no matter how horrendous.
The greatest passage in the Bible without question is Rom 8:17-39 which speaks of the glory of hope in the midst of the horror of suffering. In this passage Paul gives reason after reason for believers to never give up hope because of the work of the Triune God in creation.
As we live in the midst of horror such as Christchurch and Japan we must not fall into the trap of seeking simple theological answers, of standing as prophets in judgment condemning the victims as if it is direct judgment from God on sin, of trotting out trite answers. Rather, we must walk with those who suffer, grieving with them, comforting, supporting, helping, and praying. What should dominate are compassion and hope, not judgment and harsh calls for repentance. We must allow others to minister to us when we are weak, walking with our fellow human pilgrims in frailty and weakness, but never giving up on the hope of a new world and Jesus' love for us. We must serve, feed, love, comfort, and care.
Neither should we panic as if all this means Jesus is about to return. Perhaps he is, but that should not bring fear but hope, for the redemption of the world is near. Whether he is about to return, or it is a 1000 years away, we need to live full on for him, ready for these events in every moment, for you never know when they will hit.