Since charisms are given to build up the Church, there is no necessary connection with personal sanctity. Saints, sinners and even unbelievers have manifested these gifts. When actually under the constraint of the Spirit of God, however, the true charismatic could not say or do anything contrary to that Spirit. No one could claim, for instance, that the Spirit of God led him to get drunk or do anything sinful, although he might at other times do such things. This is why the mystical phenomena that takes place during the life of a person is considered equivocal evidence of holiness and may even complicate a Cause for Canonization.
Individuals can also do much to discern the spirit.
As noted earlier, it is easier to dismiss a phenomenon as certainly NOT from God than it is to determine its exact origin. For the laity especially, this is generally enough. This has been true at apparitions such as Necedah, Wis. and Bayside, NY., where many Catholics knew something was wrong well before the local bishops judged them as unworthy of belief. Even without the episcopal grace and the help of a commission of experts, we can apply our sense of the faith, the general theology of the Church and the history of authentic mysticism to such phenomena. There is also going to be leaders raised up in the Body of Christ that are going to move in an authority that will be trans-denominational.