Is there warfare between believers as a community and the world?
Yes. There is a constant warfare between the believer community in general and the world in general, because they are two total opposites. Believers are also in conflict internally between the new nature, which is Holy Spirit driven, and the old nature, which still has roots in the Satanic powers of the curse.
Les explains that Satan never gives up and will use even good things, so it can be an evil spirit rather than the Holy Spirit speaking. The persuasion to return to legalism did not come from the Holy Spirit who brought them out of paganism, but from the same evil spirit that previously held them. Les teaches that every believer faces constant warfare between the new nature, which is Holy Spirit driven, and the old nature, which remains rooted in the Satanic powers of the curse. This warfare also exists between the believer community in general and the world in general, because they are two total opposites, so believers are up against two forces constantly. Even among believers, Paul says the spirit drawing them into a false gospel is not the same Spirit that brought them out; it is the opposite, as verse 8 states, "and this persuasion cometh not of him that calleth you." Verse 9 then brings the warning.