The rift between biblical characters' experience and modern day readers is so vast they seem remote and inapplicable. What could the wanderings of Samuel in the Old Testament teach a modern day father of two with 20 days' holiday a year?

The first point to make is that the broader life lessons are as relevant as they ever were. Samuel learnt to trust the Lord. Gideon learnt to rely on Her. Samson learnt where his strength came from. David learnt to praise in all situations. Daniel learnt to be faithful. Nehemiah learnt to hope. The experiences are vastly different. But the lessons are applicable.

But JI Packer takes a different approach. "The link is God himself," he writes in the devotional version of his classic, 'Knowing God'. "For the God with whom they had to do is the same God with whom we have to do."

Thus begins a series Packer runs over the next few days on the changeless nature of God. He takes readers through his "changeless character", "changeless name", "changeless truth", "changeless ways" and "changeless purposes".

He is resolute that God has not, will not and cannot change. "A person of goodwill may grow cynical and callous. But nothing of this sort happens to the Creator. He never becomes less truthful, merciful, just or good than he used to be. The character of God is today, and always will be, exactly what it was in Bible times."

In a philosophical sense this throws up several issues for the reader. How can a loving God not be influenced by the sorrows and desires of those She loves? Surely being able to love means being affected and therefore in some way changed by the pleas and desperation of those you love? In ths way it seems callous for God to remain unchanged.

Packer does not address these philosophical questions head on. Instead he finds comfort in God's immutability.

"When we read our Bibles, we need to remember that God still stands behind all the promises, demands, statements of purpose and words of warning that are there," he writes.

"His aims and principles of action remain consistent. He does not at any time act out of character. Out ways, we know, are pathetically inconstant – but not God's."

He adds: "This thought brings comfort as we enter into the perplexity of each day. Amid all the changes and uncertainties of life in a postmodern age, God and his Christ remain the same – almighty to save.

"But the thought brings a searching challenge to. If our God is the same as the God of New Testament believers, then our Christian conduct and witness should rise to the same level as theirs."