Children need to know they are safe. It's a primary responsibility of parents to not only keep their children safe but to help them feel safe as well. To accomplish the latter, I started singing a short song to my kids every night before bed. It goes, "You're safe. You're warm. You're loved." The lyrics get repeated several times in my house as the kids settle down to rest. The reassurance of safety helps them relax and sleep.
We are all like little kids. We all want safety, but Peter and John are less concerned with their well being than they are with the well being of the Good News. After being confronted by the high priest and others in authority, Peter speaks with courage truth to power. These leaders can (and do) make life very difficult for Peter, John, and the other disciples. However, Peter doesn't cower in the face of danger. Instead, he takes a risk and proclaims salvation comes from Jesus Christ, the one these men had rejected.
Peter was not playing it safe! He was willing to speak with boldness and those gathered knew he must be silenced. With threats and a stern talking to Peter and John are allowed to leave but only because the Sanhedrin cannot risk the wrath of the people who were turning to Jesus.
And then we read that the disciples returned to their community which began to pray, "Now, Lord, consider their threats and enable your servants to speak your word with great boldness" (Acts 4:29). Boldness?! Really?! They didn't ask for comfort. They didn't ask for protection. They didn't even thank God for getting them out of a dicey situation. They prayed for boldness.
God does not call us to safety. God does not call us to quietly go about our lives of faith. God does not call us to comfortable living. God calls us to take up our cross and to do so boldly.