Sin is real.
Sin is deep and dark and ugly, lurking in our hearts as well as that of any terrorist.
Because of it, we need a Savior no less than they. God uses such events as a wake-up call. We need to repent and be prepared at all times, for death could come to us suddenly and without warning. God invites you and me and all people everywhere to trust in Jesus as our only Savior from sin, to believe that He will forgive our sins and grant us eternal life for Jesus' sake. God uses such events to turn evil into good.