There are many things in life that we only notice when they fail us, such as lifts, microphones, cash dispensers and flush toilets. Recently, after plodding through airport terminals long enough to earn me air miles, I've been reminded that feet fit into that category.

Feet are vital – over an average lifetime we walk between 75,000 and 100,000 miles – and any problem with them seriously affects our life.

It's hardly surprising, then, that the Bible makes 162 references to feet in the Old Testament, and 75 in the New Testament, including 27 references to the feet of Jesus. After all, because it is our feet that take us where we go, they speak of our lives.

Let me offer five thoughts on feet.

First, feet speak of committing our life to Christ. In the ancient world there was no action more profound than to fall or kneel at someone's feet. It was a gesture of humility – even humiliation – in which you acknowledged that they were your master, a dramatic physical expression of the words 'you are my lord'. In the New Testament, many people fall at the feet of Jesus (for example Matthew 15:21-28, Mark 1:40-45, Luke 10:38-42, 17:16, Revelation 1:17). While we cannot physically bow at the feet of Jesus today, no true Christian life begins without us falling spiritually at his feet.

Second, feet speak of commencing our life to Christ. We 'get to our feet' to act. There's a practical dynamic there: feet are all about doing and going, acting and reacting. One urgent and overlooked truth about Christianity is that it demands action. The Christian life is led by faith, but it is expressed in works. Many people talk about what they would like to give and do for God and his church but, alas, are still endlessly talking when their end comes. The truth is that the ultimate issue is not using our tongue to talk, but our feet to walk. Act for God: don't let the grass grow under your feet.

Third, feet speak of continuing our life for Christ. John Bunyan called his famous book The Pilgrim's Progress, and it pictures the Christian life as just that: the progress of an individual, step by step, on the long, hard road of life. As an evangelist I often have people tell me that they've decided to follow Jesus. I'm delighted. I'm even more delighted when, years later, I hear from some pastor or friend that they are still walking with the Lord.

The Bible talks about feet in the Christian walk. Proverbs 4:26-27 (NIV) says, 'Give careful thought to the paths for your feet and be steadfast in all your ways. Do not turn to the right or the left; keep your foot from evil.' It gives encouragements: Psalm 119:105 says, 'Your word is a lamp for my feet, a light on my path,' and Psalm 119:133, 'Direct my footsteps according to your word; let no sin rule over me' (NIV). We are given the Bible to illuminate even the darkest paths we must tread. Indeed, God does more than offer wisdom, he promises to come alongside when the road gets hard: 'He will not let your foot slip – he who watches over you will not slumber' (Psalm 121:3 NIV).

Note, too, that in our treading the road of life, we must help others find their feet on it. Romans 10:15 (quoting Isaiah 52:7) says, 'How beautiful are the feet of those who bring good news!' (NIV). Here's a quote from Billy Graham: 'The highest form of worship is the worship of unselfish Christian service. The greatest form of praise is the sound of consecrated feet seeking out the lost and helpless.'

Fourth, feet speak of the cost of our life for Christ. Feet in the Bible are often viewed negatively. In an age of sandals, feet got sweaty, soiled and were, in every sense, unclean. At the end of the working day you or your servant (if you had one) washed your feet clean. This is the background to Jesus' washing of his disciples' feet (John 13:1-17), an action so outrageous that it lacks any precedent in the ancient world.

There's a message here about involvement that parallels our expression of 'getting your hands dirty'. It's easy today to seek to respond to others from behind the protection of a computer or phone screen. Yet our world needs reality, not cosy virtuality. We need to be present in church services, to shake hands with people, to embrace the unloved and to go to see the lonely. Our Christian faith must be not only worked out but walked out, and that comes with a cost in wounds, bruises and dirt. It's a challenge to remember that when the risen Jesus appeared to his disciples, he showed them his own pierced feet (Luke 24:39-40). Do our feet bear evidence that we have served?

Fifth, feet speak of the conclusion of our life for Christ. We must commit, commence and continue the Christian life and bear its cost. But we can also look beyond the often painful and hazardous road that lies before us to its final and glorious conclusion.

In the face of trial and temptations we can be encouraged by Romans 16:20 (NIV): 'The God of peace will soon crush Satan under your feet.'

Many smartwatches alert us when we've spent too long at our desks and it's time to get to our feet and walk about. We need the spiritual equivalent. Around the Lord's banquet table in eternity there will be a time to put our feet up, but not until then. In the meantime, let's rise and walk for Jesus.

Canon J.John is the Director of Philo Trust. Visit his website at www.canonjjohn.com or follow him on Facebook, Instagram or Twitter.