I started to read Mindful Motherhood by Cassandra Vieten to learn coping skills for when I get pregnant. Mindfulness is the core of DBT so I think this quote from the book sums up the purpose of DBT:

"In a way, mindfulness is like learning to surf. By riding the waves of experience, rather than fighting them, you get a lot less battered about. You still experience each of them, to be sure -- a big wave still feels like a big wave, and a small one feels like a small one -- but learning how to let go and ride the waves helps keep you from being caught up in the riptides of agitation, obsessive worrying, rage, or avoidance that can come from wrestling with those wave." (pg 4).

I also relate it to being stuck in quicksand in a swamp by yourself. You're still alone in a swamp, but you don't have to be stuck in the quicksand. Instead of fighting it (which will make you sink), you stop fighting and try to float. Then you can gently get out of the quicksand and start working on finding a way out of the swamp.