You are right up to a point: We do have a responsibility to work for a better world, and to use the abilities God has given us to turn back evil. In the midst of some very difficult and discouraging times, God told His people to "seek the peace and prosperity of the city to which I have carried you" (Jeremiah 29:7).
But have you ever asked yourself why our world has so many problems? Why do we have so many wars and conflicts? Why can't people seem to get along? Even our best efforts at peace often lead nowhere, and human history is littered with the wreckage of broken dreams and shattered promises. Why is this?
The reason isn't just because something is wrong with the world (although that's part of the problem). The real reason is because something is wrong with us within our own hearts and minds. The Bible says, "What causes fights and quarrels among you? Don't they come from your desires that battle within you?" (James 4:1). Our basic problems are spiritual, and that is why our greatest need is to turn to God. Only He can change our hearts and He will, as we turn in faith to Christ.
Have you discovered this in your own life? Don't let pride or anything else keep you from Christ. He wants to change you from within and then use you to help change our world.