One of the roles of the Holy Spirit is that of providing us opportunities to witness to others who Jesus is and what he has done. These opportunities are called divine appointments. They are not accidental encounters, but willed moments designed by God. How many of these have we kept and how many have we missed? For the most part, these divine appointments are not known to us ahead of time. They seem to just happen. It may be a casual encounter with a person at the doctor's office, while waiting for an appointment. It may be initiated by a name that suddenly comes to mind and persists during the day. We will probably only  know if these are divine opportunities in hindsight. But the important point is to be attentive to the move of the Spirit in our lives. Then in faith act on these impulses. In time we will become more sensitive to the grace of the Spirit, discerning what is of him and what is not. To prepare, pray each day "Come, Holy Spirit, use me today."