The deepest, most spiritual meaning of purity is to “be detached from all creatures, free of a fixation on oneself and on others.” (Edith Stein Collected Works: Woman, p. 203)
This purity is so necessary to attaining union with God. It is a matter of the heart. The heart must not be allowed to be captivated by creatures, no matter how fascinating they may be. The soul longing for union with God will live among creatures and be occupied with them with all charity, but will not allow the heart to become attached to them or seek gratification in them.
The most challenging part of this virtue is the detachment from ‘self’ which we carry around with us all the time and are never wholly free. This detachment requires us to renounce our preoccupation with ourselves: our way, our wants, our comfort, our rights -to name a few.
When we become attached to something it prohibits our ascent to God. It is the virtue of purity that will help us to take flight and reach God.