hope

"What, then, about the "hope of righteousness" for which we wait through the Spirit? Notice that it does not say that we through the Spirit hope for righteousness. Rather, we wait for the hope of righteousness by faith, that is, the hope, which the possession of righteousness brings." ~Ellet J. Waggoner

The sum of Hebrews 6.4-6 is that if one rejects and despises all this power, having once known and tasted it, it is impossible to renew him again to repentance.