So would it easier to just change one variable instead of what you are doing, which is changing two?
Direct promises of salvation = God is going to save so long as an unbeliever believe.
No direct promises of healing = God may or may not heal a believer, even if the latter believers, depending on his sovereign will.
In both cases, whether churches/believers are carnal or not plays no role.
As you can see from my recent posts, the problem I see is in the general state of the church. In most cases, the Holy Spirit is grieved at what is happening, with departure from sound doctrine, relying on ritual and ceremony, and a general lack of purity and holiness among church members.
I believe that the answer is to ditch the man-made structures and organisation, stop spending thousand of dollars on maintaining buildings and programmes, and get right back to where the disciples were at the beginning of Acts when they were in the upper room waiting on God for the outpouring of the Holy Spirit. They didn't try to set up a "Christian" club, or have organised ritualistic, ceremonial services. All they did was to wait on God in prayer in obedience to what Jesus told them, "Wait in Jerusalem until you are empowered from on high". So they waited for as long as it took, and finally, the Holy Spirit came, and the rest is history.
I believe that the church in general has become so corrupted by fables, traditions, humanist thinking, ritual and ceremony, factions, etc., that the only answer is to ditch the lot, sell the church buildings to community groups, and to gather in private homes to just wait on God for a general "reboot" of the Christian faith, based on the sound doctrine of the Gospel.
What this will mean is a sharp division between the religious who want to continue as they are, and the true believers who want to restart with prayer and waiting on God for what He wants to do with them. What will result is an "official" apostate church, and an "underground" true fellowship of believers who are fully committed to Christ. In that fellowship, we will see a powerful re-emerging of the supernatural gifts, because those fellowships will be where God wants them to be, uncorrupted by the world, humanism and false religion.