A believer does not have to be living in sin to be backslidden, they can be backslidden when they stop hearing God's voice and stop walking by faith. Rebellion starts in the heart of the believer when they stop listening to God. They go against what God has established through the authority of His word and in many cases without doing it deliberately. Rebellion leads believers to certain lifestyles as a Christian. They can be rebellious, yet live morally upright and call that righteous living. They can work hard, raise a family and make lots of money and be a partaker of their labors and still have a rebellious heart toward the things of God. They may reap what they sow and call that being blessed by God, when in God's eternal reality it is no more than wood, hay and stubble because the grace of God was not involved.
God will always condemn Adam and the flesh because they are condemned already, but God will build up and edify the one new man who is in Christ. When God offends those that live in the flesh, they get upset and don't like it and they reveal the rebellion in their heart. God always has a plan to wean His children from milk to get them into the meat of His word. The children of Israel had this problem under Moses and God sent leaness into their souls (Ps 106:12-15). Some children rebel and don't want God's plan because they like the milk and like where they are at, but they always find themselves complaining and murmuring about something. There is always something they don't like about someone. They compare themselves with others inwardly yet outwardly try to justify their discontentment. This is the way of the flesh and of those children that have not been weaned.
When a believer goes through a trial or some kind of suffering, it is not for their sake but rather for the sake of God's word that is in them in the form of faith (Ps 18:30, 2Sam 7:21, Mk 4:17). It is not our trial but the trial of our faith that we have received from God (1Pt 1:7, Gal 2:20). If we did not have the word of God resident within, there would be nothing for God to try. God doesn't try our flesh or our old sin nature, but he tries the inner man that is begotten of God according to the incorruptible seed (Eph 3:16, 1Pt 1:23). God is in the business of sending fiery trials (1Pt 4:12) just like He did with the (3) Hebrew boys in (Dan 3). God was proving their faith and look at the confession and words that came out of their mouth, 'God is able to deliver us but if we perish, we perish'. They didn't get all upset and say, 'What are we going to do, this is so difficult, the fire is so hot and we don't have a chance to make it out'. The only reason God allowed Satan to do what he did to Job was to try the integrity of His word and make Job a showcase of His grace.
James 1:2-4 'My brethren, count it all joy when ye fall into divers temptations; Knowing this, that the trying of your faith worketh patience. But let patience have her perfect work, that ye may be perfect and entire, wanting nothing'.