Some of the BA students in college have been writing about the impassibility of God, which has prompted not a few discussion in the Common Room over coffee and snooker.  One of them has written three blog posts about it, here, here and here.  A good article I have read on the subject can be found here.  A further post can be found here.  There is such a wealth of information on the internet, this is not an attempt at a comprehensive study of the subject, but a few thoughts in what I think is the right direction.

Definitions

The first problem we encounter is defining the slippery term that is 'impassibility' (cannot suffer).  Its origins can be found in Greek philosophy, along with 'immutability' (cannot change), in the understanding that perfection is static and supreme, immovable.  They have 'cold' overtones, of unemotional behaviour, pure logic and reason, a being totally unaffected by anything or anyone else. 
However they also have many positives, for example, they assure us of a firm foundation, consistency, confidence in God's promises, and the affirmation that God is perfect, and can get no better or worse.

A further problem is that the words are negative, telling us something about what God is not, rather than something about what he is like.  This tends to have a de-personalizing effect on the subject - after all, we usually describe one another using positive terms rather than negative (e.g. 'she has brown hair and likes pizza' instead of 'she doesn't like driving and hates cauliflower').  For us to know something about God, we have to use language we understand.  Therefore, if our language is telling people something about God that is not right (e.g. that he is cold and unaffected by his world) then we either need to define our language better, or find different words to explain the same concepts.

When encountering any thorny theological problem, the first step is usually to look at the Bible, to see if it helps us.  We will find that in this case it has the potential to make things even more confusing!

Scriptural Evidence

Scripture unequivocally states that God does not change:

'For I the Lord do not change; therefore you, O children of Jacob, are not consumed.'
Malachi 3.6 (ESV)

Every good gift and every perfect gift is from above, coming down from the Father of lights with whom there is no variation or shadow due to change.
James 1.17 (ESV)

25 Of old you laid the foundation of the earth,
    and the heavens are the work of your hands.
26 They will perish, but you will remain;
    they will all wear out like a garment.
You will change them like a robe,
    and they will pass away,
27 but you are the same,
    and your years have no end.
Psalm 102.25-27 (ESV)

Jesus Christ is the same yesterday and today and forever.
Hebrews 13.8 (ESV)

I could go on, for there are many more such verses.  They highlight a key concept for us: God is not like us.  His ways are higher than our ways, his thoughts higher than our thoughts.  Even though we are authorized by Scripture to use human language (anthropomorphisms) to describe God in ways we can understand, it does not follow that God is exactly like us, or exactly like the words we use to describe him.

A classic example is this: God is just, God is merciful.  Both are affirmed throughout Scripture, both are true.  The problem the Bible poses is this: how can God be both just and merciful at the same time, when faced with his sinful people?  It isn't that God is just one day and merciful the next: he is just and merciful all the time.  We see this supremely and perfectly on the cross, where God's justice and mercy met in the death of his Son.  The crucifixion doesn't give us a new word, like 'just-ercy' or 'mer-stice', it simply shows us how it can be that God is just and merciful at once.

Back to the problem at hand.  Just as with 'justice' and 'mercy', there is an 'opposite' to God's changelessness: his loving involvement with his people.  Throughout the prophets God wrestles with the problem of loving his people, being hurt by their rejection, wanting to punish their sins, and wanting to forgive them so they might turn back to him (e.g. Jeremiah 4.19-26).  And of course there is the love of God for his world, so great that he sent his only Son to die for his enemies.

God is intimately involved in his creation.  He was when he made it, when he walked with Adam and Eve in the garden, when he called Abraham, when he rescued his people from slavery, when he called David, the man after his own heart, when he punished his people for turning away from him, sending them into exile, when he brought them home again.  And, of course:

And the Word became flesh and dwelt among us, and we have seen his glory, glory as of the only Son from the Father, full of grace and truth.
John 1.14 (ESV)

So what next?

This rather long post is coming to an end, do not fear!  We need to find a way of expressing the truths about God's changelessness, his difference from his creation, whilst at the same time not denying his involvement in that creation, supremely in his Son Jesus.

I suggest that instead of 'impassibility' (cannot suffer) we say 'sovereignty', and instead of 'immutability' we say 'faithfulness'.  Starting with the second, the whole reason the Bible emphasizes that God does not change, is to affirm his faithfulness to the covenant he made with his people: 'God doesn't change, so what he promised yesterday he promises today, and will promise tomorrow.'  Unlike we humans who break our promises, God never does.  Once he has spoken, that is it for eternity: his words never pass away.

And yet, God remains free always to act in surprising ways, for it isn't our understanding that will never change, but God himself who will never change.  Further - and this is the crunch - God was free to submit himself to the powers of history, in Jesus.  As Jesus said, at any point the Father could have sent legions of angels to protect Jesus.  His suffering (and suffering it was - read the ends of the gospels) was not forced upon him by the world, but by his and the Father's will.

Just as with the 'problem' of God's justice and mercy, in the cross we see a glimpse of how God was both God (totally different to his created things) and man (at the mercy of bloodthirsty creatures).  At any moment Jesus could have saved himself, as he was taunted to do by the Pharisees and scribes.  But he didn't.  He chose to suffer with us his people, he chose to be obedience to his Father.  At all times God remained sovereign and faithful - and free.

Let us never imagine that we can define God so accurately that we can restrict his freedom to be himself.  Everything we say about God is only transitory, is only partial - only when we are with him in his kingdom will we finally know as we are fully known.  Until then, let's do the best we can, knowing we will always fall short.