I arrived an hour late but that wasn't surprising given the fact that I'd had to negotiate a severe snow storm on the way. And I was visiting a church on the front line in a warzone after all.

It was spring 1993 and I was making my first trip to the Croatian town of Karlovac. It was a visit that proved to be a life-changing experience because it brought me into contact with a remarkable couple who showed me what it can mean to trust God as your Father.

For Croatia's small evangelical population the bitter civil war that erupted following the break up of the former Yugoslavia proved both a challenge and a God-given opportunity.

That's certainly how Ladislav Ruzicka viewed his ministry. Ladislav was the supervisor in a car parts business until God called him to pastor two small Baptist church about an hours drive away from Zagreb. The war broke out soon after he arrived but he and his wife Melanija quickly came to the conclusion that they should stay. This was in spite of the fact that around 10,000 people fled the city and some 200 civilians were to die. It certainly made for a very different form of ministry. On one occasion for example Ladislav urged a group of Croatian soldiers to leave their bunker in his back garden and take shelter in the church. Seconds later an artillery shell blew the same bunker to pieces.

On another occasion Melanija's father was repeatedly stabbed and her 16-year-old sister was brutally raped by a group of Serbian soldiers. But despite the constant danger this incredible couple continued to reach out to all sides of the ethnic divide, without bitterness or favour.

Ladislav and Melanija risked their lives repeatedly as they sought to care for those they met. When Croatian soldiers arrived to camp in the churchyard Ladislav offered them hospitality. But he cared for others too, conducting many funerals for those of Roman Catholic, Serbian and Orthodox backgrounds. Not surprisingly his ministry won him a great deal of recognition. A local newspaper survey in 1996 listed him as one of the city's 20 most respected people – the first time the list had ever included a Protestant pastor.

I will never forget that first visit. It was the first of many but It is still etched indelibly in my mind. There was such a stark contrast between the warmth of their welcome and the shell holes around the church. And even though a sniper shot someone dead as we hurried from our car they seemed to be a walking embodiment of peace. It was a remarkable experience.

So why did they stay? Ladislav seemed to sum it up some months later when I made contact, following news reports of a particularly heavy night's shelling. "Do not worry my brother," he told me. "We trust our heavenly Father".

It left me wondering if I trust Him that much. It's a question I often find myself asking on Father's Day, for in many ways it sums up what it means to be a Christian.