The Catechism in Questions & Answers

204. What is the gift of the Holy Spirit?

A distinction must be made between the Holy Spirit as a person of the Godhead and the Holy Spirit as a gift of God. The Holy Spirit as a gift of God is a power that emanates from the triune God. The believer who receives this gift is at the same time filled with the love of God.
Baptised individuals who receive the gift of God, thereby also receive childhood in God.

Holy Spirit: see Questions 198. et seq. Child of God: see explanation of Question 530. Holy Sealing: see Questions 515. et seq.