Scripture explicitly identifies the Son as God. In the prologue to the gospel of John, for example, we read, “In the beginning was the Word, and the Word was with God, and the Word was God” (John 1:1). Here, the “Word” is identified as God (“was God”) and at the same time distinguished from God (“with God”). Who is this “Word”? Verse 14 reveals the answer: “The Word became flesh and dwelt among us, and we have seen his glory, glory as of the only Son from the Father, full of grace and truth.” The Word is Jesus the Son.
There are many other ways that Jesus is identified as God by the authors of Scripture. He is, for example, identified as the one the Old Testament speaks of as Yahweh. One example must suffice. The gospel of Mark begins with a quotation of Isaiah 40:3. In the original prophecy, Isaiah is comforting the people with a promise that one day Yahweh will come to Israel. They are told to “prepare the way of the Lord.” The word “Lord” here is a translation of the Hebrew name Yahweh. In the gospel of Mark, Jesus is the One who fulfills this prophecy. John the Baptist prepares the way of the Lord Jesus, who comes to Israel. Jesus is thus identified as Yahweh, who has now come to Israel as He promised.
It is also significant that throughout the New Testament, words, deeds, and properties are attributed to Jesus that are properly predicated only of one who is God. He is worshiped (Matt. 2:2). He encourages His disciples to pray to Him (John 14:14). He forgives sin (Matt. 9:1–8; Mark 2:1–12; Luke 5:17–26). He is the Creator (John 1:3; Col. 1:16). He sustains all created things (Col. 1:17). He is sovereign over nature (Matt. 8:23–27). He will be the judge on the last day (John 5:22; Acts 10:42). Scripture could not affirm these things to be true of the Son if the Son were not God.
Fourth, Scripture expressly teaches that the Holy Spirit is God. This claim has been disputed by heretics just as much as the claim that the Son is God, but the authoritative Word of Scripture is our standard, and what it teaches is the basis for our faith. Many Christians are aware of the way in which the Holy Spirit is identified with God in Acts 5:3–4, where lying to the Holy Spirit is equated with lying to God, but some Christians incorrectly believe that this passage is the only biblical evidence for the deity of the Holy Spirit. It is not. Space constraints prevent a full discussion of every relevant passage, but a few may be noted.
Compare, for example, Isaiah 6:8–10 with Acts 28:25–27. Isaiah presents a statement by Yahweh in his prophecy. In Acts, Paul attributes the statement to the Holy Spirit. In other words, what Yahweh said is what the Holy Spirit said. We see something similar by comparing Psalm 95:7–11 with Hebrews 3:7–11. What Yahweh says in Psalm 95, the author of Hebrews attributes to the Holy Spirit.