The Catechism in Questions & Answers

202. What does it mean to say that “the Holy Spirit is the power from on high”?

The designation “power from on high” indicates that the activity of the Holy Spirit incorporates the powerful intervention of God. As the “power from on high” (Luke 24: 49), the Holy Spirit moves and fills human beings, and strengthens them in the endeavour to live in accordance with the favour of God and prepare themselves for the return of Christ.