Does God discipline believers when they fail?
Yes. Believers who sin or fail are not utterly chastised or cast out as under law, but God deals with them in love. He will discipline when they fail if they do not respond, and He may move from one level of discipline to another, leaving it up to the believer.
Les explains that this is the difference between grace and law. Under law, picking up sticks on the Sabbath brought death by stoning, but believers are not under that. If we sin or fail, we are not going to be utterly chastised or cast out. Instead, God deals with us in love. He will discipline when we fail if we don't respond, and He'll move from one level of discipline to another, yet it is still up to us as a believer. We have intense liberty that few in Christendom understand.