It is often worthwhile picking issues that are topical in our modern world that generate good discussion and are of interest to young people. Such as what Paul teaches about family attitudes between husband, wife and children (e.g Eph). Or, for example, in Genesis 1:28 God blessed humankind and said to them to be fruitful, fill the earth, and subdue it and rule over it. Everyone has a view of how well or badly we have done that - how we should do it differently - and how the world would look nowadays if everyone lived by Christian principles (for example, can the benefits of space research be reconciled with Christian values whilst millions die of basic starvation)!
Another approach might be to pick certain characters, such as Peter, and follow them throughout the bible. For example, Peter is a very different character prior to Christ's crucifixion than after he received the Holy Spirit at Pentecost. But note that this approach can be very time-consuming to prepare.
A look at the different types of miracles that Jesus performed is also very interesting - for example, why did Jesus turn so
much water to wine at a wedding that had already exhausted the existing supply of alcohol

. What was the spiritual meaning behind the miracle, what can we learn from it, what does it mean to us personally today, etc..
Whatever the topic, think of lots of questions to ask people. This way people really get to ponder on the issue. Avoid insinuating that people are either right or wrong with their views, or allowing any mockery. The point is that the more people's views are encouraged and brought to light the more opportunity there is for God to work through these people.
It is always good to start and end with a prayer, even if it is a short, prewritten one, asking God for his wisdom and truth to prevail.
Hope this helps..