The Bible talks about two Adams: first Adam who disobeyed God and died spiritually. He raised a posterity of children like him: spiritually dead...
The book of Hebrews contains various themes to encourage its readers to have a closer walk with God. "Let us" is one of those...
God's kingdom has its own culture, its own laws, appetites, language, etc. to adopt as you immigrate into it from the dominion of darkness....