If we ourselves remain angry and then sing world peace, it has little meaning. First, our individual self must learn peace.
This we can practice. Then we can teach the rest of the world.
Most REAL change is slow. Happiness and joy are the purpose of life. If we know that the future will be very dark or painful, then we lose our determination to live. Therefore, life is something based on hope.
Material objects give rise to physical happiness, while spiritual development gives rise to mental happiness. Since we experience both physical and mental happiness, we need both material and spiritual development. This is why, for our own good and that of society we need to balance material progress with inner development.
Meditation is valuable for all of humanity because it involves looking inward. People don't have to be religious to look inside themselves more carefully. It is constructive and worthwhile to analyze our emotions, including compassion and our sense of caring, so that we can become more calm and happy.