Context

This line is written by Matthew in Matthew 10:38.

Jesus has just chosen his twelve apostles, and now he's giving them a crash course in how to preach, heal, etc. He's basically telling them here that if they want to truly be his disciples, they need to deny themselves of their material desires, and follow Jesus, both literally and figuratively. The whole "taking up the cross" part just means that it's going to be hard work.

Where you've heard it

Although Jesus was talking specifically about people who wanted to be his disciples, taking up your cross (or bearing a cross) nowadays can refer to any burden you have to carry: a secret, a punishment, a backpack full of textbooks, etc.

Pretentious Factor

If you were to drop this quote at a dinner party, would you get an in-unison "awww" or would everyone roll their eyes and never invite you back? Here it is, on a scale of 1-10.

This one can sound a little pretentious (unless, of course, you're using it ironically). But maybe sounding pretentious is just your cross to bear.