John Blanchard discusses this in his book Does God Believe in Atheists?  The argument against the existence of an all-loving, all-powerful God may be summarised as follows:-

1. Evil and suffering exist
2. If God were all-loving, he would wish to prevent evil and suffering
3. If God were omnipotent, he would be able to prevent evil and suffering
4. Evil and suffering are not prevented. Therefore, there is no such thing as an all-loving, all-powerful God

It is not incumbent on the apologist to demonstrate why or how such a God allows evil and suffering to exist. The apologist only has to show that it is not a logical impossibility.

How, in a world without God, can the atheist speak meaningfully of anything as good or evil? He can speak of things producing unhappiness or pain, but nothing can be said to be fundamentally wrong, since the definition of what is ‘wrong’ is based on a consensus, rather than any transcendent standard.

It is likely that the strong moral sense that many atheists have comes from their religious upbringing or heritage.

The argument can therefore be recast in favour of the existence of God:-

1. If God does not exist, transcendent moral values do not exist
2. Evil exists
3. Therefore transcendent moral values do exist
4. Therefore God exists

As soon as the atheist draws a distinction between right and wrong, his argument falls apart.

By the same token, the atheist is also faced with ‘the problem of good’. Suffering presents no problem in a wholly mechanistic universe, but beauty and goodness do. It is the positive, even more than the negative, that requires explanation.

But every thoughtful person asks, “Why?” in the face of evil and suffering. Bleak materialism brushes the question aside as meaningless, and the human instinct for explanation remains.

The theist confesses that there is much mystery around this subject. Granted the existence of God, we cannot expect to be able to do reverse-engineering on him to find out how or why he works as he does. He does not owe us an explanation, and our finite minds cannot fully comprehend the infinite anyway: all analogical arguments simply break down. But even if we must life with a measure of doubt and uncertainty, this does not mean that we are left entirely in the dark.

God is God

Doubters sometimes demand that, if God exists, he should manifest himself there and then in some unambiguous way. But this is to ask God to surrender the very qualities that make him God – that qualities that mean that he acts on his own terms, not ours.

If God always acted ‘on demand’ to prevent injury or ill-health, or to correct our mistakes, then this would only serve to feed our arrogance and self-centredness.

The God of the Bible does indeed have absolute sovereignty over all things. But what place is then left for human responsibility and moral choice? Scripture does not seek to resolve the tension, but accepts both aspects as givens, as in the case of Joseph.

God’s omnipotence does not mean that even he can do absolutely anything. Not even God can make a round square, or make 2 = 2 = 5. Specifically, God cannot be untrue to his own nature; ‘he cannot lie, die, or deny himself.’

God could indeed have prevented human suffering by making us all robots, or by constantly interrupting the laws of nature. But would either resulting state – extreme mechanism or extreme instability be any better than the one we find ourselves in?

Suffering and Love

How can a God of love even expose his creatures to danger, let alone fail to put an end to suffering when it occurs?

Firstly, we can concede that at least some risk of suffering is consistent with goodness. Children would not be injured and killed in road traffic accidents if their parents confined them to the home, but which is the better alternative? ‘Good persons do not necessarily eliminate all the suffering they can…Rather, they prevent suffering where it is possible to do so without harming some more important goal’ (Stephen Evans).

Secondly, the problem of reconciling human suffering with God’s love is only insoluble if we attach a trivial meaning to the word “love” and take the view that humankind is at the centre of things. God’s love is not sloppy sentimentalism, but is utterly consistent with his other attributes of purity, wisdom, and so on. God’s great purpose is not to satisfy our own appetite for what we consider to be happiness, success or well-being, but to impart himself, and so all good, to other persons.

Thirdly, God demonstrates the reality and depth of his love by his willingness to enter into and share the trauma of human suffering. He is not remote and unfeeling, but concerned and involved. He has taken on our suffering in an acute and personal way in order to bring us into a transforming and eternal relationship with himself.

Blame and Cause

When tragedies occur, God often gets the blame. But how can God be blamed for the starving millions when he has provided the means for producing more than sufficient food for everyone on the planet?

Should we blame God for deaths caused by floods famines, volcanoes and earthquakes? We should rather blame ourselves for not living within the known limits set by our environment. Our departure from the will of God has led to us living in (or forcing others to live in) unsafe places, engaging in bad farming, making bad predictions, setting up inadequate defences, and so on.

Titanic – 1500 people died. The crew ignored six warnings of drifting ice. The ship was equipped with only 20 life-boats, rather than the 32 that were originally planned, because so many would make the deck look cluttered. Therefore, the total lifeboat capacity was on 1,178 for a liner capable of carrying over 3,500 passengers and crew.

Turkish earthquake disaster, 1999 – 15,000 people killed and 200,000 others made homeless. National newspapers claimed that of 600 buildings erected by one well-known contractor, 500 had collapsed.

Aberfan disaster – the enquiry concluded that the blame lay with those responsible for building a slag-heap directly above a stream and near a school. Previous, small slips should have warned of danger. The enquiry spoke of ‘bungling ineptitude’ and said that the disaster could and should have been prevented.

Chernobyl – the official report concluded that the incident was due to a deficient safety culture throughout the Soviet design and maintenance for nuclear power at that time.

Is God to be blamed for pilot and driver error, for the adverse effects of smoking, drinking and drug-taking, for the results of sexual promiscuity, or deficient urban planning, or government corruption, or emission fo greenhouse gases?

Evil is not a substance, but an attitude that flows from the human heart. Pain and suffering can be traced back to human rebellion against God.

The Purpose of Suffering

What purpose can God have permitting evil and suffering? We cannot expect to fathom the divine mind, but we can hope to find some pointers.

Even without turning to the Bible, we can see that tragedy and disaster can have positive effects by leading to improvement safety measures, a cleaner environment, and so on. They have also drawn forth positive human reactions such as love, compassion, and selfless service.

As everyone knows, pain itself serves a salutary purpose in helping to prevent many of the worst effects of injury and disease.

In Scripture, we read of instances in which disaster directly serves God’s purpose of judgement, and therefore warn of the great day of judgment to come. Alternatively, some cases of disease or disability were allowed in order that God’s mercy might be manifested. Personal suffering often causes people to seek God. Moreover, suffering can also equip us to help and comfort others who are suffering.

Specifically, the Bible teaches that,

1. Suffering can develop confidence in God’s transcendent wisdom. Job’s experience taught him that he could charge God with being uncaring or unjust only if he showed that he could match the divine wisdom and power, Job 38:4 40:2.

2. Suffering can provide a focal point for the believer’s faith. Habakuk learned that even if all earthly goods were taken away from him, he could still rejoice in God, Hab 3:17-18.

3. Suffering is meant to be spiritually productive. There is a certain kind of maturity that only comes through the discipline of suffering.Rom 5:3-4 Jas 1:2-4.

4. Suffering sometimes takes the form of God’s disciplining of his children, Heb 12:10-12.

5. Suffering reminds us of our physical frailty, and of our dependence on God, 2 Cor 12:7-10.

6. Suffering diverts us from the temporal, and points us to the eternal, 2 Cor 4:18.

See Blanchard, Does God Believe in Atheists? 517-554