I believe Blake tries to establish a sense of direction in one's life separate from religion by introducing virtues of mercy, pity, peace, and love and how the individual is clearly influenced by these virtues. I think he’s pretty much saying that regardless of what your religion is, all humans embody these virtues internally and throughout everyday life. It’s almost like a celebration of the human spirit and the goodness we have internally.

of or relating to people or nations that do not practice Christianity, Judaism, or Islam.

1. old-fashioned + often disparaging : a person who is not religious or whose religion is not Judaism, Islam, or especially Christianity.

2. old-fashioned + disapproving : a nonreligious or uncultured person.

The origins of heathen and pagan are semantically similar. Heathen likely comes from a term for a country inhabitant—in particular, a “heath dweller.”

Etymology: Middle English hethen, from Old English hǣthen; akin to Old High German heidan heathen, and probably to Old English hǣth heath

1540s, "a tract or region of the earth," shortening of climate (or a nativization of Latin clima). It might usefully take up the old, abandoned "horizontal region of the earth" sense of climate, but it is used chiefly by the poets, and they display no evident agreement on what they mean by it.

1. An indication or warning of a future occurrence; an omen.
2. A feeling or intuition of what is going to occur; a presentiment.
3. Prophetic significance or meaning.

v. (prĭ-sāj, prĕsĭj) pre·saged, pre·sag·ing, pre·sag·es

1. To indicate or warn of in advance; portend.
2. To have a presentiment of.
3. To foretell or predict.

The verb presage was predated by a noun presage, meaning "omen." Both forms derive from the Latin prefix prae- combined with the adjective sagus, meaning "prophetic." Foretell, predict, forecast, prophesy, and presage all mean "to tell beforehand."

Every stanza ends with "for thee." This ties back in to the tittle of the poem "To Anthea" and evokes a sense of dedication among two lovers where the male figure is expressing their love for Anthea by saying they will fulfill any request they have for them, I.E. "Bid that heart stay, and it will stay," "Bid me despair, and I'll despair."

Rhyme scheme is ABAB.