Essays by Francis Bacon is exactly that: a collection of essays that detail his ideas and musings on philosophy, morality, life, and much, much more. Francis Bacon's most prominent feature was his masterful ability to twist turns of phrase using his wit. Many phrases and sayings have been plucked from the pages of his Essays and are still in common use today.
A summarized list will not do justice to the breadth of topics in this work, but some ideas he touches on include truth, death, revenge, religion, marriage, love, envy, travel, empires, wisdom, boldness, superstition, health, finance, friendship, education, beauty, and gardening, to name a few.
His work focuses mainly on the related ideas of truth, love, and unity. Each of the separate essays focuses on a specific theme, but they all generally delineate ideas about how to be a good and morally upright being—as well as ideas on how to seek after and follow truth.
When discussing religion, he says that the division that exists between people is the main cause of atheism. He specifically relates the story of the atheist Lucretius discussing Agamemnon and the violence that caused his atheism. Bacon states that, if Lucretius were around to have heard of Guy Fawkes's gunpowder plot or any other modern acts of hatred, he would have been seven times the atheist he was.
Bacon's later essays focus on living human life well: how to ethically manage a business and amass wealth, how to tend to gardens, and how to maintain beauty and grace in the world. The intent for all of these discussions, it seems, is to show people his ideas on how to live a proper, loving life that brings joy and prosperity to all a person encounters—for the glory of God and to unite humanity.