John the Baptist's Day Readings (focus text in bold):

Isaiah 40:1-11 - prophesy about John the Baptist's ministry of preparation
Psalm 80:1-7 - Turn us again, O God, and we shall be whole (a community lament)
Acts 13:22-26 - St. Paul tells Galatian converts about John the Baptist's ministry
Luke 1:57-80 - the nativity of John the Baptist and Song of Zechariah

Also referenced: John 3:22-36, John's testimony about Jesus

Cover art: "The Birth of John the Baptist" depicting Zechariah writing "His Name is John" and the Blessed Virgin, great with child, standing to the left; by Jacapo de Pontormo; oil on desco da parto; c. 1526; Uffizi Gallery, Florence, Italy

Trinity 3 Readings (focus texts in bold):

2 Chronicles 33:9-13 - the story of Manasseh's repentance
Psalm 55:17-23 - As for me, I will call upon God (an individual lament)
1 Peter 5:5b-11 - God resists the proud and exalts the humble
Luke 15:1-10 - the parables of the lost sheep and lost coin, to the Pharisees

Also referenced: "The Prayer of Manasseh" included in the 1611 King James Bible

Cover art: "The repentance of Manasseh" by Sig Lambrento, 2015, digital illustration, private collection. (Source.)

Trinity 2 Readings (focus texts in bold):

Genesis 12:1-4 - the call of Abraham out of Ur
Psalm 15 - Who shall rest upon your holy hill (a liturgy of entrance)
1 John 3:13-24 - let us not love in word, but in deed and in truth
Luke 14:16-24 - the parable of the great supper

Cover art: "The Parable of the Great Supper" by Cicely Mary Barker, 1935, oil on canvas, Waddon St. George Church, Croydon, Greater London