To walk after the flesh is to be carnally minded. This leads to frustration and ultimately death. People who walk after the flesh are not necessarily trying to do evil things, however, they have confidence in themselves , that is, in their ability and performance to achieve what they want to. To walk after the Spirit is to be spiritually minded. It leads to life and peace. To walk in the Spirit, we must have no confidence in the flesh, but rather a willingness to trust God to be in control of our lives.