We must be ever-ready to help people to understand Buddhism better. To clarify a few points is always a good thing, especially when people come around claiming that Buddhism is a negative or pessimistic religion. So here are a few points about Buddhism that are pretty much accepted across the board- and they demonstrate a religion that is as far from pessimism as you can get.
BUDDHISTS BELIEVE THAT COMPASSION IS UNIVERSAL.
To Buddhists, compassion- the desire for others to be free of suffering- is not just a human construct or accident of evolution; compassion is believed to be a universal reality which exists across the entire expanse of Samsara, which includes not just the physical earth and outer space, but also the many other realms that Buddhists believe are inhabited by sentient beings. Compassion is the keynote of the Universal Dharma which unites all truly wise beings in any world, time, or place.
BUDDHISTS ARE NOT NIHILISTS.
To Buddhists, The ultimate heart of reality is not a nihilistic void, not a lack, not an absence, but a radiant and bright space of living awareness, which is boundless and free. The experience of it excites love and compassion in any being who glimpses it. In Tibetan Buddhism, the two highest "Adi-Buddhas" or awakened beings who are closest to ultimate reality are called "Samantabhadra" and "Samantabhadri", names meaning "All-Around Goodness", or "Invincible Goodness that is found in all directions and places."
BUDDHISTS DO NOT BELIEVE HUMANS ARE INNATELY FLAWED OR EVIL.
To Buddhists, human beings are not innately flawed. They are not innately "sinful", "evil", or even prone to sins or evil. The ultimate reality of each and every human being is the boundlessness of true living freedom, far beyond deluded thoughts, and stainlessly existing alongside even delusions. This is the best possible "soil" for human personalities and lives to grow from, and it makes all acts of generosity, love, and compassion not only possible, but likely. The delusions that make people do harmful things are not permenant conditions; they are temporary conditions, and can easily be remedied if a person would only examine their own lives and motivations, something that Buddhists believe all humans are intelligent enough to do.
BUDDHISTS ARE NOT AGAINST YOU WORKING TO HELP YOURSELF.
To Buddhists, there is no ideal greater than compassion, and no vocation greater than selflessly working for the happiness and well-being of others. Before you can really do that, however, you have to understand some things about the world and yourself, and it is not considered selfish or wrong to work on yourself, before you are ready to help others.
BUDDHISTS DO NOT HATE THE WORLD.
To Buddhists, "renouncing" the world doesn't mean leaving the world or hating it; it means simply accepting that all things pass away, and not being attached to things that are, at heart, ephemeral and temporary.
BUDDHISTS DO NOT THINK THAT LIFE SUCKS.
The Buddhist notion of "Dukha" or "Suffering" is not believed to be the only reality of human life. All human lives (and the lives of all non-human sentient beings) does contain elements that are dis-satisfying, but this does not stop those lives from containing sukha, or pleasurable elements, and Buddha never denied that there were pleasurable things about human existence. He was just realistic when it came to where pleasures ended up- in the pit of boredom. People- all people- become bored of their routines and seek new horizons, hobbies, and fun things, after a point. Nothing we seek out in the name of "pleasure" really satisfies us forever. Buddha wanted to find a way of seeing life and the world that resulted in reliable, lasting peace, not temporary pleasures. Craving for temporary pleasures that never bring lasting happiness or peace was the main source of Dukha, both in Buddha's time, and today.
BUDDHISTS DO NOT EXPECT YOU TO GIVE UP THE THINGS THAT MAKE YOU HAPPY.
Even the things that you cherish, that give you temporary pleasures, don't have to be thrown out of the window, if you are Buddhist. Buddhists don't "renounce" things by destroying them; they "renounce" things by accepting new understandings about them. Once you understand and accept that your new video game, drug, book, or DVD can never bring you lasting happiness, you have seen the wisdom of the Buddhas. You can keep those things or use those things afterwards, and derive pleasure from them, but on the deepest level, you cannot become truly attached to them, in the harmful sense of the word. After a while, you may find that they lose all power over you, and you seek deeper things upon which to base your happiness. It really doesn't matter, either way; just understanding the temporary and ephemeral nature of these things is enough to create good karmic results in you, good insights, and begin you on the path to freedom.