Well, good acts are still good. Vitamins are good for you, but won't cure cancer. So it's not that works don't matter, but that they are completely inadequate. We need salvation through Jesus. And then, good acts are God's gift to us, not the other way around. As a former drug addict, I see that perspective. To be able to be happily married, work a good job, be good to my kids and all that's a miraculous gift, to me. I don't get brownie points for living a good life, rather, I thank God that I get to be alive at all and get to be spiritually healthy. The wages of sin is death, but the gift of God is eternal life through Jesus Christ.