In its comment on Acts 2:36, The Moody Bible Commentary reads:
The Moody Bible Commentary - Acts 2:36
Verse 36 is the high point of Peter's sermon. Jesus' miraculous works, His resurrection, and His exaltation indicate overwhelmingly that He is both Lord (a common title for God and applied to Jesus in Acts; see 4:33; 8:16; 15:11; 16:31; 21:13; 28:31) and Christ (the Messiah, the "Anointed One" who rescues Israel and all humankind). This was a shocking conclusion for his Jewish audience, who did not comprehend the triunity of God. Peter's conclusion reflects the high Christology of the early church, which believed that Jesus was God because of the historical evidence. Their Christology was based on personal conviction of what they knew was true, not wishful thinking.
Above, the Moody Bible Commentary appears to interpret Jesus being called "Lord" here as Peter declaring that He is God, and asserts that the Jews would have been shocked, because they "did not comprehend the triunity of God".
The verse being commented on says:
Acts 2:36
36 Therefore let all the house of Israel know assuredly, that God hath made that same Jesus, whom ye have crucified, both Lord and Christ.
The verse above has traditionally been used as a proof text for Unitarianism, because it explicitly distinguishes God from Jesus, and says that God "made" Jesus "Lord and Christ". If "Lord" here were to be interpreted as the Moody Bible Commentary seems to teach, then it would have Peter saying that God has made Jesus "God and Christ".
But, the meaning of "Lord" as applied to Jesus, in context, refers to God telling Jesus to sit at His right hand (is God sitting at God's right hand?), until God makes His enemies His footstool, a quotation from Psalm 110:1:
Acts 2:32-36
32 This Jesus hath God raised up, whereof we all are witnesses.
33 Therefore being by the right hand of God exalted, and having received of the Father the promise of the Holy Ghost, he hath shed forth this, which ye now see and hear.
34 For David is not ascended into the heavens: but he saith himself, The Lord said unto my Lord, Sit thou on my right hand,
35 Until I make thy foes thy footstool.
36 Therefore let all the house of Israel know assuredly, that God hath made that same Jesus, whom ye have crucified, both Lord and Christ.
The teaching of the passage, therefore, is that Jesus has been exalted by God to Lordship, and is at the right hand of God, a place of honor and authority. This designation of Jesus as the "one Lord" under the "one God" is seen throughout the New Testament (1 Corinthians 8:5-6, Ephesians 4:4-6), and the authors of Scripture do not conflate the position of Lord occupied by Jesus with the position of God, who has placed Him in that role.
Additionally, consider the following verse from the same sermon given by Peter that the passage in question comes from:
Acts 2:22
22 Ye men of Israel, hear these words; Jesus of Nazareth, a man approved of God among you by miracles and wonders and signs, which God did by him in the midst of you, as ye yourselves also know:
Here, Jesus is called a "man" who God worked through, and, as throughout the entire sermon, Jesus is explicitly distinguished from God, and spoken of as a separate subject. This makes the Moody Bible Commentary's interpretation of "Lord" in Acts 2:36, where Peter is supposedly rather suddenly and without explanation declaring that Jesus is God, untenable, unless one wants to present Peter as speaking in a manner which would be extremely confusing and apparently self-contradictory to an audience, which, as the Moody Bible Commentary states, "did not comprehend the triunity of God". The Jews that Peter was speaking to would have had no concept of a tri-Personal God, with one of those Persons being Jesus of Nazareth. If Peter had intended to teach such a thing in any form, the words that he chose in this sermon could hardly have been more counterintuitive to that goal, because they leave every impression that Jesus is explicitly distinct from God, and is not God, but rather, a separate subject through whom God has worked, and then exalted to Lordship.
The sermons given in the book of Acts are actually some of the strongest proofs that the early Church was Unitarian, as they speak of Jesus and God distinctly, and do not hazard to explain that Jesus actually is God (Acts 2:22, 2:36, 3:13, 3:26, 4:10, 5:30-31, 10:38-42, 13:37-38, 17:30-31). This style of preaching when Christianity was the newest, and most subject to misunderstanding, is significant, because at such a time it is even more important to be careful not to impart confusion, especially regarding the identity such an important figure. The passage in question from Acts 2, properly understood, is an example demonstrating that the early Church spoke freely of God in distinction from Jesus, because they regarded them as separate figures, with Jesus being the one Lord under the one God, exalted by the one God to Lordship at His right hand.