I am copying and linking to Lord’s Day 8 of the Heidelberg Catechism (1563).
(Making up for missing last week, being on the road, I post 2 Lord’s Days in one day)

This text comes from the Heidelblog.net publication of the Catechism (accessed 5 March 2023).
Q24. How are these Articles divided?
A. Into three parts: the first is of God the Father and our creation; the second of God the Son and our redemption; the third, of God the Holy Spirit and our sanctification.1
11 Pet 1:2. * I John 5:7.
Q25. Since there is but one Divine Being,1 why do you speak of three persons: Father, Son and Holy Spirit ?
A. Because God has so revealed Himself in His Word,2 that these three distinct persons are the one, true, eternal God.
1Deut 6:4. 2Isaiah 61:1. Ps 110:1. Matt 3:16,17 Matt 28:19. I John 5:7.
* 2 Cor 13:14.
One can either search for the tag: #heidelbergcatechism1563 or use this pre-built query to get access to the whole catechism as the Lord’s Days Questions and Answers are posted each week
Thank you