In Acts 3, Peter and John come across the lame beggar at the gate called Beautiful who had been crippled since birth. Peter basically grabs the beggar's hand and the power of God goes through the guy and heals him. The guy starts walking around and everybody sees it. The crowd of people are in awe of this miracle and now, full attention is on the disciples. Why?? Because the crowd wants to know how this happened. The crowd saw this guy everyday on the ground begging for years. Peter takes this opportunity to tell them about the Jesus they crucified. The crowd listens to the entire message and at the end of it, 5000 people give their lives to Jesus.
Peter and John weren't on a street corner handing out tracts or holding a cross. They didn't have a megaphone shouting. They performed a supernatural miracle and let that do the talking. I could go out on the street and talk to people about Jesus and people will shun or ignore me, especially if they've heard it a hundred times. But if I display the power of God, people will stop in their tracks. Once that happens, now I have their attention and they will listen. Wouldn't You?? Of course!
Paul understood this well. In 1 Cor 2:1-5, Paul was saying that working in power puts the focus on God where as us only using our words, it's easy for us to get the glory. Paul new how important it was to display God's power. It's just common sense. We talk about a supernatural God, so lets provide that evidence. I always say, rather than talk about God, how about I show you Him right now and end two years of debate.