One of the fascinating things about Christianity is how very different the great men and women of God are. George Müller (1805–1898) was not just different, he was unique.

Müller was born in the then Kingdom of Prussia (now Germany). He grew up into a young man who was frequently involved in petty crime, often to do with what we would call 'scams' and even a time in jail did nothing to reform him. However, in 1825 Müller attended a prayer meeting in someone's home where he encountered Christ. With his life dramatically transformed, Müller felt called to mission work and ended up in London working amongst Jews. An illness led to him going to Devon to recover his health and that began life and ministry in the West Country.

It became evident that he was gifted as a preacher and an evangelist, and he became the minister of a chapel. Soon, he and his wife moved to Bristol. There he became involved in creating Christian schools and supporting missionaries. Müller established 117 schools which offered Christian education to tens of thousands of children, and he continued to support a great number of missionaries throughout his life.

Müller is, however, remembered above all for his extraordinary achievements with orphans. In the Britain of the early 19th century, the combination of large families, extreme poverty and a high level of adult mortality had resulted in many orphans, most of whom ended up on the street. The state ignored them and in 1836 Müller and his wife began taking in orphans.

Their work grew in an astonishing way, and they built a home for 300 children. Soon, however, even that was not enough, and more buildings followed in Bristol so that by 1870, there were 1,700 children housed in five purpose-built homes with a total of 500 rooms. By the end of Müller's life, his homes had housed 10,000 orphaned children. Müller's commitment was not simply to house children but to clothe, feed and educate them and ultimately, where possible, to find them jobs.

This achievement alone would justify Müller's hero status, but what is astonishing is that in doing what he did he never made requests for financial support. He simply prayed that God would supply all his needs and left it to him to supply them. Extraordinarily, God did just that regularly and for decades. Müller was a meticulous administrator and his detailed accounts reveal that in his lifetime he received £1.5 million pounds in money and gifts; a figure that today would be over £100 million. Always astonishingly generous, he refused donations for his own well-being and died in near poverty.

These figures disguise an astonishing reality. There are many well-attested accounts of how, when he and his staff seemed to be on the point of running out of either food or money, last-minute unsolicited donations or gifts arrived. On one occasion Müller found himself with 300 orphans assembled for breakfast and no food at all. He simply sat them down at the table and confidently said grace. At this point, a knock at the door occurred. It was a local baker who had woken up at 2 o'clock in the morning with a feeling that he needed to bake more bread than usual and take it to the orphanage. Shortly afterwards a milkman arrived to say that his wagon had broken down outside the orphanage and he wanted to offer his milk to the children. Over the decades, Müller's ever-expanding work often ran on a hand-to-mouth basis, but it never ran into debt.

With time, Müller prayed for someone to succeed him as a manager and, having found him, handed over the reins in 1875. He then began 17 years of missionary work across the world in which he travelled over 200,000 miles teaching and preaching. Müller's funeral in 1898 brought Bristol to a standstill with tens of thousands of people standing along the route. In a different form, his work continues today with the George Müller Charitable Trust.

Müller is a challenging figure in a number of areas but the most spectacular one is how he found funding for his work without openly asking for it. It's a strategy that many Christians have grappled with. Two things must be said. First, Müller was a unique individual and this was a personal decision: he never set this out as a model for other Christian workers. He felt that this was what God wanted for him and that it would demonstrate that a miracle-working God still existed. It may also have involved an utter rejection of his pre-conversion tendency to raise money through fraud.

We are all led by God in different ways; St Paul, for instance, is open in asking for money to support Christians in Jerusalem (see 1 Corinthians 16:1–4; 2 Corinthians 8:1–9:15; Romans 15:25–31). Personally, I am in awe of Müller's decision (and must admit my faith is hugely challenged), but like St Paul I have mentioned the financial needs of my own ministry.

I am reminded of my favourite George Müller quote: 'Faith does not operate in the realm of the possible. There is no glory for God in that which is humanly possible. Faith begins where man's power ends.' Indeed that was true then and continues to be true today.

Yet there are other areas of Müller's life that are challenging. His prayer life was astonishing, and he had an extraordinarily deep relationship with God. Fundamental to this was how, despite running an enormous and complex charitable enterprise, he made sure that time with God came first.

It's hard not to be impressed by the way that Müller's faith gave him breathtaking audacity in what he planned and achieved. Most of us would have been daunted by a goal of housing a hundred orphans, let alone a hundred times that.

Finally, Müller was committed to both preaching the gospel and doing good deeds. He clearly felt no tension between sharing the good news of Jesus and working to care for orphans.

George Müller's unique life demonstrated to his contemporaries that God could be trusted. It says the same to us today.