"Orthodox Spirituality: A Practical Guide For The Faithful And A Definitive Manual For The Scholar" by Dumitru Staniloae
"Orthodox Psychotherapy: The Science of the Fathers" by Metroplitan of Nafpaktos Hierotheos [translated by Esther Williams]
"John Ruusbroec THE SPIRITUAL ESPOUSALS AND OTHER WORKS [The Classics of Western Spirituality]
"Devotio Moderna BASIC WRITINGS" [The Classics of Western Spirituality]
"Miguel de Molinos THE SPIRITUAL GUIDE" [The Classics of Western Spirituality]
I am see in all the above books a common description of the Christian life. I would add that as Christians we must go by the teachings of the Bible when it comes to being a lover of the Lord Jesus Christ. The above books are not free from error. "Test all things; hold fast what is good" 1 Thess. 5:21. Personally I love the apostle Paul and study continually his epistles/New Testament especially The Letter to the Romans and the Letter to the Galatians.
"And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God" Romans 12:2.