Those of us in the Christian walk have been given a commission, to preach the gospel to the ends of the earth. The only reason God doesn't simply take us out of this place upon acceptance of Jesus' sacrifice is so other can accept that same sacrifice. We know the truth, that truth is that all have sinned and fallen short of the glory of God. All are either for God or against God. There is no one righteous, no not one. Without belief in Christ they are going to suffer eternal damnation. If we know that they will suffer eternal torment, if we do nothing it is like having the cure for the most painful cancer and not telling them about it. It is like letting a blind and deaf man get hit by a train.
Christianity can become so simple. Almost a biword or thought in our daily lives. We are Christians, thus we try to live our lives as Christians, doing Christian like things and saying Christian like things that can actually have nothing to do with following Christ. We go throught the actions that may at one time have been genuine but now have lost that genuineness and simply becomes works that we know are the right things to do or say but have little meaning. We like the Ephesians in Revelation we lose our first love. We lose the very objective that we are here, to make disciples.
I'm not going to claim that we all need to be preachers. We do need to all be lights to those arround us. "Let your light shine before men, that they may see your good deeds and praise your Father in heaven" (MT 5:16). When Jesus went out he went in power and signs and wonders. He didn't just preach. The primary way we show God's love is my actions not words. However, there comes a point when the love of God must be told, for they will not glorify your Father if they don't know you have one.