Romans 8:6

For the mind of the flesh is death; but the mind of the Spirit is life and peace: "Mind of the flesh" -'to set the mind on the flesh' (Nor). Fleshy thinking and striving (Vincent p. 90) The person who loves the things of this material world, more than God. (1 John 2:15; 2 Timothy 3:4)

"is death" -spiritual death (for even faithful Christians experience physical death). So much for envying our non-Christian neighbors that 'get' to spend their Sunday's boating on the river, sleeping in, fishing, etc...it may look like they are "livin", but God says they are "dead men".

Remember the "mind of the flesh" includes more than the 'gutter life'. It includes good moral neighbors that refuse to serve God and it also includes self-righteousness and religious hypocrisy. (Matthew 6:1).

"mind of the Spirit" -"spiritually minded" (KJV); 'whereas to set the mind on the Spirit brings life and peace' (Nor). Those who allow themselves to bring their thinking into line with God's thinking. (2 Corinthians 10:5; 1 Peter 2:5; 1 Peter 3:15; 1 Peter 4:8).