Willing to Suffer (2) (Mark 9:38-50)

The Old Testament forbids man from harming himself, but our Lord seems to be contradicting His command to Israel by advocating that we cut off a body part that may cause us to stumble.  Does the Lord really want us to cut off body parts?  How is the Lord different from Baal when the priests of Baal cut themselves in 1 Kings? If our Lord does not desire us to maim our bodies then what does our Lord mean when he talks about cutting off parts of our body that lead us into sin?