Yes—capitalization is significant, because all-caps LORD signals Jehovah, while capital-L lowercase-ord 'Lord' in 'Lord God' represents a different Hebrew name of deity (Adon/Adonai/Adon-o).
Les Feldick repeatedly instructs readers to watch the capitalization of names of deity because the KJV translators used it to distinguish Hebrew names. In Genesis 15:1 the all-caps LORD is Jehovah. In Genesis 15:2, 'Lord God' uses a different form, which Les identifies as Adon/Adonai/Adon-o. The distinction is not a typo.
Genesis 15:1 — Shows the all-caps LORD (Jehovah) addressing Abram in a vision.
Genesis 15:2 — Shows the differently capitalized 'Lord God' in Abram's reply, the form Les identifies as Adon/Adonai.
Genesis 2:4 — Introduces 'Lord God' with an all-caps LORD, marking the first use of this combined divine name.
In the Hebrew Old Testament, God is revealed through more than one name, and the King James Version reflects that with different renderings. Genesis 1 repeatedly uses the simple name 'God.' Genesis 2:4 introduces 'LORD God'—the KJV's all-caps rendering of Jehovah combined with God (Elohim). Genesis 15 shows both forms close together: verse 1 says 'the word of the LORD' came to Abram, and verse 2 records Abram answering, 'Lord GOD.' The Bible itself does not explain the English capitalization, but the underlying Hebrew text does use different divine names.
Les says the capitalization is there for a reason and urges viewers to watch it. Whenever the KJV prints 'Lord' with all capitals (L-O-R-D), it stands for Jehovah. Translators used 'Lord' because Jewish writers, out of awe for the sacred name, would not even write it. Les also teaches that Jehovah is, with only one or two exceptions, God the Son and is the Redeemer/communicator. In Genesis 15:2, however, 'Lord' is not in all capitals and is not a typo; it is the Hebrew name Adon, Adonai, or Adon-o, a different name of deity. In Genesis 18, Les comments on the capitalization of 'Lord' and says he would tend to agree with translations that use a small 'l' because Abraham likely did not yet know one of the three visitors was Jehovah.
Les explains that the KJV translators generally used the word Lord for Jehovah out of courtesy to old Jewish writers, who had such awe for the divine name that they would not even write it. So whenever the KJV shows capital L-O-R-D, it means Jehovah. Les also teaches that Jehovah is God the Son and the Redeemer.
In Genesis 15:1 the word Lord is all caps and is Jehovah. In verse 2, Abram says 'Lord God,' and now the word Lord is not all-caps. Les says this is no typographical error; in Hebrew it is the name Adon, or in some places Adonai or Adon-o, a different name of deity.
Genesis 1 uses 'God' (Elohim), a plural word that includes the Trinity. At Genesis 2:4 the text changes to 'Lord God' with the Lord all-caps. Les calls this an intentional introduction of Jehovah, the Redeemer, the person of the Godhead who communicates with man.
Les notes that the KJV capitalizes Lord in Genesis 18:3, but some translations use a small l. He tends to agree with the small-l rendering, because the surrounding verses give no hint that Abraham knew at that moment that one of his three visitors was Jehovah.
The Genesis 15:2 Distinction
Les points to Genesis 15:2 where 'Lord' is not all-caps and explains that this is not a typo but the Hebrew name Adon/Adonai/Adon-o, a different name of deity.
Abraham Before Jehovah
Les notes that in Genesis 18:3 some translations render 'Lord' with a small l, and he tends to agree because Abraham may not yet have known that one of his three visitors was Jehovah.
Progressive Revelation of Deity
Les shows the Bible progressively reveals names of deity; Genesis 1 uses only God, while Genesis 2:4 introduces 'Lord God' with all-caps Lord.
Jehovah Revealed as Redeemer
Les explains that translators used 'Lord' for Jehovah because Jewish writers would not write the name, and that all-caps LORD in the KJV represents Jehovah, the Redeemer.
Elohim and Lord God
Les explains that Genesis 1's God is Elohim, a plural name for the Trinity, while Genesis 2's 'Lord God' continues Elohim but adds the new name.
Why the Jews Said 'Lord'
Les explains that the Jews substituted 'Lord' for Jehovah because the name was so holy they would not even breathe it, and that all-caps LORD throughout the Old Testament is Jehovah.
LORD Equals Jehovah, God the Son
Les teaches that whenever the KJV uses L-O-R-D in capital letters, it is Jehovah, and Jehovah is God the Son (with only one or two exceptions).
Genesis 2:4 Is Not a Misprint
Les shows that the change from God in chapter 1 to Lord God in Genesis 2:4 is intentional and sets apart a special person of the Godhead.
Genesis 2:4: These are the generations of the heavens and of the earth when they were created, in the day that the LORD God made the earth and the heavens,
Introduces the composite name 'LORD God' (Jehovah Elohim) after Genesis 1 used only 'God.'
Genesis 15:1: After these things the word of the LORD came unto Abram in a vision, saying, Fear not, Abram: I am thy shield, and thy exceeding great reward:
Uses the all-caps LORD to identify the word of Jehovah coming to Abram.
Genesis 15:2: And Abram said, Lord GOD, what wilt thou give me, seeing I go childless, and the steward of my house is this Eliezer of Damascus?
Uses 'Lord God' with Lord not all-caps, the different form Les identifies as Adon/Adonai.
Genesis 18:3: And said, My Lord, if now I have found favour in thy sight, pass not away, I pray thee, from thy servant:
Shows why Les discusses whether Abraham recognized the visitor as Jehovah.
No. Les Feldick says the capitalization is intentional. All-caps LORD is Jehovah; capital-L 'Lord' in 'Lord God' is the Hebrew Adon/Adonai/Adon-o, a different name of deity.
The KJV translators used 'Lord' for the sacred name Jehovah because Jewish writers, out of awe, would not write or pronounce the name. Whenever the KJV has capital L-O-R-D, it represents Jehovah.
Les teaches that Jehovah is, with only one or two exceptions, God the Son. He also refers to Jehovah as the Redeemer and the communicator, the person of the Godhead who speaks to man.
Watch the Teaching: The Meaning of Adonai: Understanding God as Master