Even if someone knows the Dhamma well taught by the Buddha and lives by it, they will cross the ocean of samsara with great difficulty and reach Nibbana.
Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo.