Is Still Worth It To Invest In a 401k?

I'm in the process of deciding whether or not I would like to set up a 401k account with my employer. As we all know, we are in a recession right now and I'm cautious with my money. I'm still in my twenties, but I was still in college as I watched many Americans loose 50% or more of their 401ks money due to the stock market. Right now, I'm not too enticed even though my employer is willing to match some of the money I put into that account. Why have your future ride on something unstable like the stock market. I mean this is my future and social security will definitely not exist for people like me. So the question is, it worth it to invest in a 401k. Also, have Roth IRA account. Thanks. Also, what about the stable value investment? It would yield any return, but at least I won't loose anything.