Theme: The Holy Spirit is true and eternal God, worship him and do what he says

Belgic Confession Article 11

Biblical evidence for the deity of the Holy Spirit

Divine names: He is called God (cf. 2 Peter 1:21 & 2 Timothy 3:16; Acts 5:3-4; Isaiah 63:10 & Hebrews 3:7)
Divine attributes: That which is true of God is true of him (cf. 1 Corinthians 2:10-11; 3:16; Isaiah 40:13 & Romans 11:34; Hebrews 9:14; Job 33:4; John 3:5; Psalm 139:7-10)
Divine works: He does that which God does (cf. Genesis 1:2; Psalm 104:30; Job 26:13; 34:14-15; Acts 20:28; 1 Corinthians 2:11; John 16:8-11; Romans 8:15-16)
Divine honour: He is worshipped as God is worshipped (Matthew 12:32; 1 Peter 4:14; Ephesians 4:30)

The filioque clause
The original Greek text of the Nicene Creed (381) did not include the phrase 'and the Son.' This filioque clause first appeared in the Latin translation issued by the Third Council of Toledo (589). The addition was made to further define the procession of the Holy Spirit. It is based on the Biblical evidence found in John's Gospel (14:16; 15:26; 16:7, 13-15), Romans 8:9, Galatians 4:6 and Philippians 1:19. This revision is received by the Reformed and Presbyterian churches but is not received by the Eastern Orthodox Churches.