That verse, in context, is referring to those who are not saved, those who are not being led by the Holy Spirit.
Galatians 5:18-20 But if you are led by the Spirit, you are not under the law. Now the works of the flesh are evident: sexual immorality, impurity, sensuality, idolatry, sorcery, enmity, strife, jealousy, fits of anger, rivalries, dissensions, divisions, envy, drunkenness, orgies, and things like these. I warn you, as I warned you before, that those who do such things will not inherit the kingdom of God.
Tell me, do you believe that salvation is gotten by works? Or is salvation by faith?
Eternal life is gotten through the Holy Spirit:
"...every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven men. Anyone who speaks a word against the Son of Man, it will be forgiven him; but whoever speaks against the Holy Spirit, it will not be forgiven him, either in this age or in the age to come." - Matt. 12
Every day has its challenges. All are tested. No one is exempt.
Unless one is tuned into His Omni-Beacon and constantly receiving its course headings for the heart, drifting off course either to the left or to the right becomes deceptively easy.