As physical illness needs the right medication to be cured, cyclic existence can only be stopped with practice of the Dharma. To counteract defilements and attachment, one must exert a sharply opposing force in order to be effective. The process of exerting this counteracting force is the path leading to the cessation of suffering.
In other words, the purpose of undertaking Dharma practice is to cease the endless cycle of rebirth and death, not unlike what the right medicine is to a patient.
~ Depicted from Luminous Wisdom Book Series 1