Matthew states that this child (Jesus) is God (God with us):

“Behold, the virgin shall conceive and bear a son, and they shall call his name Immanuel (which means, God with us)” Matthew 1:23 & Isaiah 7:14

John is likewise explicit in the prologue to his Gospel:

“In the beginning was the Word, and the Word was with God, and the Word was God.” John 1:1 & “And 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.” John 1:14

Some of the disciples called Jesus God directly.

“Thomas answered him, “My Lord and my God!” John 20:28, and “Simon Peter, a servant and apostle of Jesus Christ, To those who have obtained a faith of equal standing with ours by the righteousness of our God and Savior Jesus Christ” 2 Peter 1:1

The book of Hebrews is most emphatic that Jesus is God. Hebrews 1:8, applying Psalm 45:6 to Jesus Christ, states: “But to the Son, He [the Father] says: ‘Your throne, O God, is forever and ever.'” Other parts of Hebrews explain that Jesus is higher than the angels (Hebrews 1:4-8, 13), superior to Moses (Hebrews 3:1-6), and greater than the high priests (Hebrews 4:14-5:10). He is greater than all these because He is God—along with the Father. and the Holy Spirit.

The doctrine of the Trinity means that there is one God who eternally exists as three distinct Persons — the Father, Son, and Holy Spirit. Stated differently, God is one in essence and three in person.  Essence is what you are, person is who you are. So God is one “what” but three “whos.”

“Father, the hour has come; glorify your Son that the Son may glorify you, since you have given him authority over all flesh, to give eternal life to all whom you have given him. And this is eternal life, that they know you, the only true God, and Jesus Christ whom you have sent. I glorified you on earth, having accomplished the work that you gave me to do. And now, Father, glorify me in your own presence with the glory that I had with you before the world existed.” John 17:1-5