Both the Church and the Scriptures bid us to test things to see if they are of the Spirit.
One of the reasons a bishop does not just lay hands on a man and ordain him to the diaconate or the priesthood without years of training is that the time in the seminary, (or as a postulant and novice in a religious community for men or women) is that the time during the trianing is a time to test ones vocation. First one will start out with a weekend or week long retreat to see how the community or seminary functions, and attend other seminars or religious functions to test the waters. The time in preperation works both ways, first for the aspirant to see if he or she has a vocation to religious life, and also for the Church and religious superiors to see if one has what is needed to live a life of total devotion to Christ and the Church. One of the very best places to start is with ones spiritual director or confessor. “Interviewing” priests or brothers to see what and how they felt called by Christ. Most of all, spend time with our Lord in the Blessed Sacrament, and ask that His will be done, not yours.