Purification and Grace
Purification is undertaken by self-analysis and introspection. It is a purification of body, mind, and soul. The goal is to become spiritually or ceremonially clean. The process can take a lifetime for most people. No one is without issues. Even the best of Saints struggled with purification.
Read "The Interior Castle" by Teresa of Ávila or "The Story of a Soul" by Therese of Lisieux. Both wrote about their struggles with purification. They also offered their advice on purification and spiritual development. Both experienced "the dark night of the soul" before mature spiritual development and, ultimately, their sainthood.
Having said all of this, if you think you have to be completely pure and clean before beginning the contemplative life, it is most likely you will never start on the journey. The life of a contemplative is consumed with introspection and reflection. Contemplatives seak God and seldom feel totally clean or worthy. The solution is a focus on GRACE.
After studying these books cited by the Saints, you might end up asking yourself about the "false self" and the "true self." A major theme in Paul’s writings is that two selves are competing for leadership in our lives. In Ephesians, Paul refers to the old self versus the new self.
"Ephesian 4:22-24 (NRSV) 22 You were taught to put away your former way of life, your old self, corrupt and deluded by its lusts, 23 and to be renewed in the spirit of your minds, 24 and to clothe yourselves with the new self, created according to the likeness of God in true righteousness and holiness.”
The Christian Contemplatives journey is about deconstructing the false self and discovering the true self. So, where do you start? You might read the books I cited, "The Interior Castle" by Teresa of Ávila or "The Story of a Soul" by Therese of Lisieux. Also, Father Thomas Keating has several books that are of paramount importance, in my opinion.
Lastly, as I said before, focus on GRACE. Your sins are forgiven because of your belief and trust in Jesus Christ. If you confess your sins to Jesus, they are forgiven. Now "clothe yourselves with the new self ." Your job is to pray for spiritual development and Trust in Jesus; God's job is to be trustworthy and to answer your prayer according to His Will.
Christian Contemplation Introduction