The doctrine of the Trinity is encapsulated in Matt 28:19 where Jesus instructs the apostles:"Go therefore and make disciples of all nations baptizing them in the name of the Father and of the Son and of the Holy Spirit."
This isn't only proven in Matthew,but appears elsewhere in the New Testament as well as writings of the early christians who understood and believed this doctrine.St Ignatius of Antioch(a follower of John the apostle) wrote:"to the Church at Ephesus in Asia.........chosen through true suffering by the will of the Father in Jesus Christ our God."(Letter to the Ephesians 1[A.D 110].
After the Resurrection,Thomas called Jesus:"My Lord and my God".
[John 1:1]"In the beginning was the Word,and the Word was with God,and the Word was God.[2]The same was in the beginning with God.[3]All things were made by him:and without him was made nothing that was made.
[14]And the Word was made flesh,and dwelt among us.

"For as the Father hath life in himself,so hath he given to the Son to have life in himself."(John 5:26).From this we can infer that Paul's words "who alone hath immortality(1 Tim 6:16),do not refer to the Father alone but to the one and only God which the trinity is.For "who hath immortality" is said in the same way as "who performs wonders alone"(Ps 72:18).If this is said of the Father only,then how can what the Son say be true,that "whatever the Father does,the same the Son also does likewise"(John 5:19).Or which of his wonders is more wonderful than raising the dead?Yet the Son says"As the Father raises the dead and gives them life,so also the Son gives life to whom he will.(John 5:21)
The place which makes it most evident that the Holy Spirit is not a creature is the one where we are bidden not to serve the creature but the creator(Romans 1:28)."The Lord your God shall you adore,and him only shall you serve"(Deut 6:13).If we are forbidden to serve creatures,then the Holy Spirit is not a creature,since all the saints offer him such service,according to the apostle's words,"For we are the circumcision,serving the Spirit of God."(Phil 3:3)
Could anything be more sacrilegious than to have the effrontery to call the members of Christ the temple of a creature who is inferior,in some people's opinions,to Christ himself?For Paul says "Your bodies are the members of Christ"(1 Cor 6:15).But if things are members of Christ are the temple of the Holy Spirit as prononced in 1 Cor 6:19,then the Holy Spirit isn't a creature and we owe him service."Glorify God therefore in your bodies."(1 Cor 6:20).
It cant be argued that his saying"I shall ask the Father,and he will give you an advocate" really suggests that the Holy Spirit is absolutely sufficing himself:"When he,the Spirit of Truth comes,he will teach you ALL truth".(John 16:13)
Jesus is equal to the Father as he said"Believe in God,believe in me too"(John 14:1)which amounts to "Just as you believe in God,so too in me,because i and the Father are one God."
The Holy Spirit is unmistakably called Lord:"And the Spirit is Lord"(2 Cor 3:17).
In the Apocalypse,Jesus identifies Himself as "the beginning".St John in his gospel identifies Jesus as "Word"of God made flesh and that nothing was made without Him.
Many disregard this because of John 14:28:"The father is greater than I".To them this statement so obviously means Jesus is not God.But is this really what our Lord was saying?In theology,this text can be understood in two ways.
First,being 'greater' than another does not have to mean one is essentially different from the other,as when we say man is distinct from an animal.Greatness cao refer to one functioning in a greater way quantitatively or even relatively in comparison to another,without there being a distinction.For example in Matt 11:11 it is said that no man is greater than John the Baptist,yet he that is least in the kingdom is greater than he.
Another simpler way one can legitimately interpret this text is to point out that John 14:28 seems to be emphasizing the humanity of Christ(his human and not his divine nature).
The same Jesus who can say,"I and the Father are one" in John 10:30-as God-can say,"The Father is greater than I" in John 14:28-as man.

John 5:18:"He called God his Father,making himself equal with God."
Phil 2:6-10:"his equality with God not something to be grasped on to,but emptying himself and becoming man"[Paul is talking about the humility of Jesus being divine.He assumes his readers already knew Jesus to be equal with God the Father]
Both John and Paul clearly believed this.And in the New Testament,Jesus is given the title Lord as uniquely applied to Yahweh in the Old Testament;and he calls himself"the Lord of the Sabbath"(Mark 2:28)

The final proof of Jesus divinity is in Revelation 21:6-7) where he reveals himself to John as Almighty God in plain terms:"And he said to me, 'It is done! I am the Alpha and the Omega.......He who conquers shall have this heritage,and I will be his God".

Gen 1:26-The God(YHWH-Elohim is the 'singular' plural of God who is one) said,"Let us(refrence to the Godhead) make man in our image,in our likeness.
Dt 6:4-"Hear O Israel the LORD our God the LORD is one(Shema Israel Yahweh Elohim Yahweh echad).Elohim is plural for God.Yet God is saying He is one.
John 1:1-In the beginning was the Word,and the Word was with God(Theos) and the Word was God(Theos).[LATER in John's Gospel "The Word was made flesh(in the womb of the virgin)].
Jesus is worshipped in scripture,which if he was not God, would be a sin.Luke 24:50-52,Matt 28:16-18,Matt 2:2,Matt 14:33.
Jesus and the Holy Spirit are explicitly called YHWH(Engish-Yahweh) in scripture.Matt 1:23,Titus 2:13,Rom 9:5,Heb 10:15-18.
Yahweh will never share his glory with any other[Mat 25:19]Therefore go and make disciples of all nations, baptizing them in the name of the Father,and of the Son,and of the Holy Spirit.

Based on scriptures,we know Jesus sits at the right hand of God.
The expression 'right hand' does not indicate a lower place,but a relationship of equality.It is not and cannot be understood as a physical right hand,but rather the Scripture emphasizes the magnificence of the Son's great dignity.
Christ is the power of God and the wisdom of God(1 Cor 1:24),and the image of the invisible God(Col 1:15),and the brightness of his glory(Heb 1:3) and the one whom God the Father has sealed(John 6:27),whom the Father has stamped with the image of His Person.
Paul writes these not to introduce any division of natures,but to prove that the union of Father and Son is without confusion.
GOD IS ONE.

Jesus called God his Father,and the jews had a problem with it,because they said that thus he was claiming EQUALITY with God.
In Revelations,Jesus identified himself as the Alpha and Omega,THE BEGINNING and the end,who is,who was,and who is to come,the Almighty.
St John identifies Jesus as THE WORD of God made flesh and that nothing was made without him.
Now if we substitute the bolded words in -'In the BEGINNING,God created heaven and earth....',we can say 'In Jesus,God created heaven and earth'.
The Holy Spirit is already present with the words "and the spirit of God moved over the waters".And so we have the Holy Trinity present at creation.In Jesus,God created heaven and earth....and the spirit of God moved over the waters.Since Jesus is God's mouthpiece here on earth,God the Father"speaking",i.e"God said" signifies creation by the Father,through the Son,by the Holy Spirit since "it was good".