Why are you here? This isn't meant to be a metaphysical mind-bender, but it is a genuine question that many of us struggle with. We want to serve God. But in our busyness we so often get bogged down in the 'what' of life - 'what do you do'…or 'what do I want to be…'?

But your 'why' is what lies beneath the surface of your many decisions. It is what informs what you do. Many of you reading this will say you aren't sure what your 'why' is yet. You might be jealous of people who seem so sure of what they are going to do in the future; or paralysed with anxiety that you might miss God's plan for your life.

When you know 'why' you are here, then the 'what' either falls into place or becomes dramatically less important. 'Where should I go for my Foundation Years?' Well, if your 'why' doesn't clearly shape that, then it might not be that important. 'Should I do Core Medical Training or GP Training? Again, if your 'why' doesn't shape that, then God may well use you equally in both.

as Christian healthcare students, why are we here?

Having struggled with questions of calling, significance and guidance throughout her medical training, the medical missionary Helen Roseveare had just arrived on her first assignment in Africa. She got off the plane and met the local field director on the runway, who said to her:

If you think you have come to the mission field because you are a little better than others, or as the cream of your church, or because of your medical degree, or for the service you can render the African church, or even for the souls you may see saved, you will fail. Remember, the Lord has only one purpose ultimately for each one of us, to make us more like Jesus. He is interested in your relationship with Himself. Let Him take you and mould you as He will; all the rest will take its rightful place. ( 1)

The Westminster Shorter Catechism asks, 'What is the chief end of man?'. Answer: 'to glorify God, and to enjoy him forever'. (2) We glorify God through obeying the scriptural 'calls'. We are called to be holy; (3) to obey the Great Commandment to love God and neighbour; (4) and to fulfil the Great Commission to make disciples. (5) How do we do this? Through being made more into the image of Jesus Christ. (6)

The famous early theologian Augustine said pithily, 'Love, and do what you will'. In other words, we don't need a divine calling for every decision, for every 'what' in our life. We can glorify God in our specialty, and do the specialty that we will. We can glorify God in our relationships, and marry who we will. 'What' we do isn't as important as our pointing to the 'why' we do it — to the glory of God.

'what' we do flows out of 'why' we are here

Jesus himself knew his 'why', which meant saying no to good things. When people begged him to stay to heal more people and to perform more miracles he answered, 'I must proclaim the good news of the kingdom of God to the other towns also, because that is why I was sent' (Luke 4:43). The apostle Paul's calling and passion was 'to bring the nations to obedience' (7) to preach to the Gentiles. Rather than being paralysed by his options (remember, he could travel freely across the whole empire), his 'why' constrained him. (8)

Similarly, we are made with a 'shape', and we should seek to find what that is, to play our part in God's giant jigsaw. Our gifts, experiences, passions and personality all contribute to understanding our 'why'. (9) 'What' we do then flows out of 'why' we are here, which will differ for each of us. Four CMF members I've spoken to recently have vividly and passionately outlined their 'why' — one knows it's to develop people in teams; another's 'why' is to be a leading endocrinologist; another is passionate about social justice in the healthcare sphere; another describes their purpose as an advocate for vulnerable children who have been subject to abuse. Their 'why' keeps them going when the 'what' gets difficult, pertinent in the pressured environment of the NHS. For many, their 'why' isn't only relevant to their medical work. Their 'why' shows itself in other areas such as leisure and church involvement.

So what's this got to do with leadership? Overall, knowing our 'why' helps us grow in leading ourselves. But it's also vital to understand how we are shaped to best lead others. (10) The result is immensely freeing. You don't need to compare yourself to people who are doing 'bigger' or 'more significant' things than you. You can see when a decision between two options might mean that both or neither are right. And you are free to say no! Medics are often asked to be involved in all sorts of areas, but reflecting on the 'why' can help us say 'no' to roles that perhaps others can do, with confidence that we are seeking to be obedient to what only we can do.

how to discover your 'why'

First, ask yourself questions like 'What makes me angry?' or 'What roles do I usually gravitate towards and why might that be?' Before bed, reflect on when you felt most alive in the day — during that placement, lecture, or conference. For example, 'that interaction with the family on the ward felt really satisfying. I didn't perform a dramatic procedure on that child, but I sense I'm good at connecting with parents'. Over time, you will begin to learn what makes you tick and this might help you piece together a career path that makes best use of your strengths.

Second, ask those close to you what they think you are passionate about, particularly Christians who share your desire to honour God. They might reflect on how you speak or how you interact with certain people. Insightful friends can often see your 'why' more clearly than you can, perhaps what gifts God has given you.

Third, let CMF help! We have a wealth of resources, knowledge and most of all real, living members you can connect with. Ask to have a coffee with the GP who works in the local addiction service. Skype the director of the mission hospital. Listen to what they are passionate about. Look for someone whose 'why' might resonate with yours and ask them to walk with you. With CMF you can also take opportunities to grow in your faith, using the online resources and opportunities like Global Track, Speakers' Track, Writers' Training and much more.

And finally, remember that understanding your 'why' is a lifelong process. Try something and get honest feedback on it. Take some risks. What have you got to lose? As a Christian you can work from your identity, not for your identity. From the security of your identity in Christ you can answer the call to steward your gifts and go out into the harvest field to make disciples. Time is short, our life is a mist, (11) and we are being called to give our lives away in response to all God has done for us.

John Greenall is CMF National Field Director and a paediatrician in Bedfordshire