The simple answer is - a "Marian" faith. As we know, the Mother of Christ is the great exemplar of trusting faith. What was happening when the Angel Gabriel came to her? Our traditions say that she was praying. I remember, a few years ago, seeing a beautiful painting by a Catholic artist depicting that meeting. He showed Mary carrying water back from the well. I believe she was praying, but that painting made a valuable point. God chooses His time! It is not up to us to guess when He will visit us in a dramatic way. I remember a talk by Fr. Tom Forrest (at a Conference for priests) saying a similar thing. St. Ignatius, he said, had his moment in a cave, and we will have ours. There is usually more than one such visitation in a lifetime. The Holy Spirit, according to St. Thomas Aquinas, can "come upon us" more than once after Baptism and Confirmation. Sometimes we will be brought to a deeper conversion of heart. Perhaps something like this could be identified with the awareness of a vocation of some kind. Sometimes we are visited in a dramatic way through serious illness or bereavement.
Advent is a time of watching and waiting, but most of the watching and waiting in our lives happens in the midst of ordinary events. Sometimes we are not praying and not even thinking about God, although there needs to be a kind of habitual readiness on our part. Sometimes we might be washing up or sitting down for a well-earned rest, when, suddenly, we become aware of a Presence. This is the moment to LISTEN. We need the kind of faith that is ready to listen, and it is the kind of faith that is part of who we are and what we are about in this world. Whatever we are doing when these graces come, we need to be ready, but this state of readiness can only be built up within us through prayer and daily repentance. Sin can block it out or make it seem almost too vague to be noticed. Lack of prayer means that we may miss these moments completely.