What does it mean to say that someone is totally depraved? In short it means that humanity is dead in sin. We are neither willing nor able to merit God’s favor by acts of righteousness for we are all unrighteous (Rom. 3:10-19, 23; Eph. 2:1-3; Col. 1:21; Tit. 3:3). This does not mean that people cannot do any good things–there is relative good (i.e. helping the old lady across the street)—however, we cannot and do not do good things before God apart from Christ. As the Heidelberg Catechism says, we by nature are prone to hate God and neighbor, and daily increase our debt.
I have noticed that many people speak of depravity in terms of what we do. In explaining depravity of man they talk of homosexuality, murder, slander, etc. I don’t think this is helpful. Instead of speaking first of what we do we should instead speak of who we are. We are depraved, therefore we do sinful things.