Faithless generation, what does it mean to have faith?

Devotion on book of Mark 9:30-37

The Christian's life should be one of faith, of victory, and joy in God. “Whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith.” 

Men may profess to believe the gospel; but unless they are sanctified by the gospel their profession is of no avail. If they do not gain the victory over sin, then sin is gaining the victory over them. The thorns that have been cut off but not uprooted grow apace, until the soul is overspread with them.