I found him on sale in my local High Street, strategically placed among other Christmas gifts. He is 'Inflatable Jesus,' a model of Christ that inflates to 50 centimetres (20 inches) tall.

Shoppers are encouraged - for £7.50 ($9.75) - to 'Inflate him, play with him and pray with him!'

Described as an 'adult novelty', the packaging warns "not for play by children," and carries speech bubbles declaring "He is always there for you" and "His love is unending". Shoppers are also advised that the novelty "floats on water".

I admit I was surprised to find 'Inflatable Jesus' among the Christmas stocking fillers. Maybe, in a way, I should have been encouraged - a poll reported by Christian Today last Christmas showed that four in ten British people did not know Jesus even featured in the nativity story.

But here are four things that Inflatable Jesus 'taught' me:

Some Christians are shocked by it. When I posted a photo on social media, there were a range of replies. "I find this offensive," one Christian responded. Another declared: "This is appalling. I am deeply disturbed that anyone would find amusement in this."

Others saw a funny side. One vicar responded: "There's no future in it - we'd only let him down." Another priest said she had bought one for each of her godchildren last Christmas.

The novelty gift gives insights into our society. A Christian writer commented on what 'Inflatable Jesus' said about our self-focussed world. He said: "Inflatable Jesus will never judge you. Also available: bedtime Jesus that reads stories with you as the hero, and Affirmation Jesus who reminds you how you're the centre of the world."

But primarily, Inflatable Jesus challenged me about the importance of Christians talking about their faith this Christmas - and not in a preachy or self-righteous way. We need to show that faith in Christ is more than hot air, that it's not something to be put away when not needed and it's not just for Christmas.

I'm not offended or outraged by Inflatable Jesus - nor do I find it especially funny. I'm more puzzled and curious. Puzzled that in our supposedly secular age, a religious figure can still be a money-earner, and curious about the thinking behind the novelty.

I'm also challenged to want to tell people more about the real Jesus, the Word made flesh who came to live on earth, to die and rise again to bring us everlasting life. The Jesus who preached, healed and gave honour to people on the margins of society.

The challenge for Christians and churches is to tell that truth in fresh ways again every Christmas and thoughout the year.

I'm pretty sure that Inflatable Jesus is not part of that storyline.

Rev Peter Crumpler is a Church of England priest in St Albans, Hertfordshire.