Verse 7 refers back to verse 5. Prior to consecration, we walked in gross sins like fornication, inordinate affection, and covetousness. Verse 8 lists less gross, though nonetheless dangerous, sins the new creature is to put off. If practiced, these sins can also keep one from getting life.
The gross behavior of verse 5 is more easily recognized, whereas the sins of verse 8 are usually not as apparent, for they are only occasionally manifest. However, all of the sins in verse 8 are dangerous and could be outward manifestations of grosser sins (verse 5) being secretly indulged in. Statements from the mouth are not hidden from the Church. In summary, verse 5 lists deeds of a wrong lifestyle. Verse 8 lists sins of the mouth that seem to be less important but are actually symptomatic of a serious condition.