Answer:
1.Theme is the lesson or message of the poem.
2.The word "grandeur" means grandness or magnificence. In "God's Grandeur" Hopkins conveys his reverence for the magnificence of God and nature, and his despair about the way that humanity has seemed to lose sight of the close connection between God and nature during the Second Industrial Revolution.
3.Popularity “God’s Grandeur”: Written by Gerard Hopkins, a famous poet, and Jesuit Priest, “God’s Grandeur” is famous for its divine appraisal and presence of God on the earth. It was first published in 1918 in the collection Poems of Gerard Manley Hopkins. The poem explores the relationship between the divine world and the world of nature. It illustrates how divine presence infuses its spirit and refreshes the world, despite the attempts of mankind to destroy its real fabric through materialism. The popularity of the poem lies in the fact that it praises God for the role He plays to restore the world destroyed by human greed and love for materialism.