Now With Mindfulness Of Buddha Eliminate The Three Obstacles
You and others should teach those future sentient beings [i.e. those who surely include us in this Dharma-Ending Age] with transgressive karmas many, for eliminating transgressions thus, teach to enable them to be mindful of Buddha. With mindfulness of Buddha thus, eliminate all karmic obstacles, retribution’s obstacles and afflictions’ obstacles.
(Meditation’s Secret Essential Methods’ Sūtra)
 What Are The Three Obstacles?