Facing the Opposition (Answering September's questions one by one)
3 - Who was Jesus praying to in the garden? (In other words, they are attacking the triune nature of God: One God, in three Persons.)
What does God say in His word, the Bible?
There is only one true and living God, period.
Genesis 1:1 In the beginning God created the heaven and the earth.
Exodus 20:1-3 And God spake all these words, saying, I [am] the LORD thy God, which have brought thee out of the land of Egypt, out of the house of bondage. Thou shalt have no other gods before me.
Deuteronomy 6:4-5 Hear, O Israel: The LORD our God [is] one LORD: And thou shalt love the LORD thy God with all thine heart, and with all thy soul, and with all thy might.
The true and living God never changes.
Malachi 3:6 For I [am] the LORD, I change not; therefore ye sons of Jacob are not consumed.
Daniel 7:13-14 I saw in the night visions, and, behold, [one] like the Son of man came with the clouds of heaven, and came to the Ancient of days, and they brought him near before him. And there was given him dominion, and glory, and a kingdom, that all people, nations, and languages, should serve him: his dominion [is] an everlasting dominion, which shall not pass away, and his kingdom [that] which shall not be destroyed. (Compare Revelation 1:12-18.)
James 1:17 Every good gift and every perfect gift is from above, and cometh down from the Father of lights, with whom is no variableness, neither shadow of turning.
The true and living God is ...
The Father
Old Testament - Psalm 2:7, Proverbs 30:4, Isaiah 64:8
New Testament - Matthew 3:16-17, Luke 11:2, John 17:4-5
The Son
Old Testament - Isaiah 7:14, Isaiah 9:6, Isaiah 44:6
New Testament - John 1:1,14, 1 Timothy 3:16, Hebrews 1:8
The Holy Spirit
Old Testament - Genesis 1:2, Isaiah 61:1, Joel 2:28-29 (See Acts 2:16-18.)
New Testament - John 14:16-17, Acts 2:4, Acts 5:3-4
These three are One.
Matthew 28:19, Colossians 2:9, 1 John 5:7
There is still only one true and living God ... there always has been.
1 Corinthians 8:5-6, Ephesians 4:4-6, James 2:19
This question is definitely one of the most common of questions asked by an LDS member. And from my own personal experience, their approach in it comes with the attitude of, "I gotcha now!" Listen, the answer is very simple: Jesus was praying to God, the Father. He was not praying to Himself; the Bible does not teach that, nor do we believe that. One distinct Person within the Godhead was communicating with another.
God, the Son, left the glory of Heaven (John 17:5; See also Isaiah 42:8 regarding the glory of God.) and humbled Himself by becoming a man (Philippians 2:5-8). This did not change His Godhood (Hebrew 13:8). Jesus took on humanity, while sustaining His Divinity. When He prayed on earth, He prayed to God, the Father, who is in Heaven. Within the Bible you see communication between the Persons of the Godhead, even outside of the Gospels. (Genesis 1:26, 3:22, 11:7-8; Isaiah 6:8)
LDS neighbor, what about the passage in Hebrews 1:8? Who is speaking? Who is God? Who is He speaking with? And once again, who is God?
There are two common misconceptions that need to be addressed.
1 - The three persons within the Godhead are three separate Gods. There are numerous passages in the Bible which refute that doctrine, some of which have already been mentioned. (There is only one God, period.)
2 - The three persons within the Godhead are not actual persons, but personalities only. This doctrine is referred to as Modalism: God reveals Himself through three different modes. This heresy has been around for a long time and has been refuted with passages in the Bible, some of which have been mentioned. (There is only one God, and there are three distinct Persons referred to as God.)
Worship God in spirit and in truth,
One Clay Soldier among many