Contradiction with Exodus 20:3
This verse commands worship of no other gods, which contradicts the worship of an "unknown god" mentioned in Acts 17:23.
Exodus 20:3: Thou shalt have no other gods before me.
Contradiction with Deuteronomy 6:5
This verse instructs to love the Lord your God with all your heart, implying exclusive devotion, conflicting with the acknowledgment of an unknown god in Acts 17:23.
Deuteronomy 6:5: And thou shalt love the LORD thy God with all thine heart, and with all thy soul, and with all thy might.
Contradiction with Isaiah 45:5
This verse states there is no God besides the Lord, contrasting the notion of an unknown god in Acts 17:23.
Isaiah 45:5: I [am] the LORD, and [there is] none else, [there is] no God beside me: I girded thee, though thou hast not known me:
Contradiction with Jeremiah 10:10
Declares the Lord as the true God, opposing the idea of an unknown god considered by the Athenians in Acts 17:23.
Jeremiah 10:10: But the LORD [is] the true God, he [is] the living God, and an everlasting king: at his wrath the earth shall tremble, and the nations shall not be able to abide his indignation. [true...: Heb. God of truth] [living God: Heb. living Gods] [everlasting...: Heb. king of eternity]
Contradiction with John 14:6
Jesus asserts being the only way to God, which challenges the worship of an unknown god in Acts 17:23.
John 14:6: Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me.
Contradiction with 1 Corinthians 8:5-6
States there are many so-called gods, but for Christians, only one God, countering the concept of an unknown god in Acts 17:23.
1 Corinthians 8:5-6: For though there be that are called gods, whether in heaven or in earth, (as there be gods many, and lords many,)
Contradiction with Isaiah 42:8
God declares He will not give His glory to another, contrasting with the Athenians' worship of an unknown god described in Acts 17:23.
Isaiah 42:8: I [am] the LORD: that [is] my name: and my glory will I not give to another, neither my praise to graven images.
Paradox #1
The moral conflict in Acts 17:23 might arise from the idea of acknowledging other religions. Some people could see a contradiction in Paul recognizing another god's altar while promoting his own beliefs. This could seem inconsistent with solely worshiping one God, as Christians are generally taught.