When it comes to poker strategy — be it for tournaments or cash games — we often hear the generic advice to "play more aggressively."
Betting and raising often puts pressure on your opponents and puts them in uncomfortable spots, whereas checking and calling usually doesn't. That's one reason why an aggressive style is often recommended over a passive one. There's also the fact that by betting you give yourself two ways to win a pot — either at a showdown with the best hand, or by forcing an opponent to fold — whereas just calling or checking down to the end requires you to have the best hand to win.