Why is an unbeliever an enemy of God?
An unbeliever is an enemy of God because he does not have faith. Scripture states that without faith it is impossible to please God, and those in the flesh cannot please Him. Mankind rejects God's clear laws and wants nothing to do with them, leaving the unbeliever outside of Christ and at enmity with God.
Les teaches that the unbeliever is an enemy of God simply because he does not have faith. This is an absolute: Hebrews 11:6 says without faith it is impossible to please God. Les connects this with Romans 8:8, where those in the flesh cannot please God, describing lost mankind outside the Gospel and outside of being positionally in Christ. He also notes that mankind's human nature totally rejects God's clear and precise laws and wants nothing to do with them, so unbelief leaves a person unable to please God.