Proslogium

The Medieval cleric Anselm writes vividly about the existence of God and the divine in this superb manual of faith.
The Proslogium (in English: Discourse on the Existence of God) was first published in the late 11th century. Each short chapter of this text contains poignant thoughts and statements about the divinity. As a whole, the treatise examines and reflects upon the differing qualities and virtues of God, discussing Anselm's perceptions of the divine and His influence on the world and the sum of existence. 
At the time of publication and for centuries to follow, Anselm's thoughts were controversial for proposing an ontological argument in favour of God's existence. The very fact the debate is being had and exists day by day, is alone enough to confirm the existence of the Heavenly Father. Although sparking criticism in some quarters, the context of the text's publication - for Christian lay people seeking a rational explanation for the Lord's presence - have led many to laud and appreciate St. Anselm's conclusions. 
The influential thoughts and contemplation of Christian belief by Saint Anselm remain as fresh and vibrant as ever. The translation by Sidney Norton Deane to modern English present in this edition was first published in 1903, and is considered authoritative.