In this reading from the Acts of the Apostles, Luke makes two rather intriguing and unexplained remarks: "they had been prevented by the Spirit of the Lord" and "the Spirit of Jesus would not allow them." After recounting the vision of the man from Macedonia, Luke speaks in a clearer though undeveloped way: "concluding that God had called us..."

These remarks most probably refer to some form of the "discernment of spirits". In his First Letter (1Jn 4:1), St John urges us to "discern the spirits to see if they come from God." In his letters, St Paul frequently speaks of the Holy Spirit and charismatic gifts in such a way as to imply the need of discernment. The Old Testament speaks of the need to discern between true prophets and false prophets.

In general, the discernment of spirits implies a spiritual maturity, allowing one to evaluate all the interior thoughts, inclination, tendencies, impulses, which fill our hearts and minds and draw us to greater good, a more liberating love of God, a concerned and caring love of our brothers and sisters, or to the opposite of all that God would desire for us and expect from us.