Jesus Christ is the second member of the Godhead. Though the word "Trinity" is not found in the Bible, THE THREE MEMBERS OF THE GODHEAD ARE. The word "Trinity" is a term Christians use to speak of the Oneness of God who is the Father, Son and Holy Spirit, yet one. The word "Trinity" is the Christian's way of expressing the Biblical fact that God is these three - the Father, Son and Holy Spirit - but one. This term "Trinity" is interpreted many different ways and needs much clarification to see whether by its use one has distorted the Scriptures or not. There is much controversy over the term.

God is one God, yet the Father is God, the Son is God, and the Spirit is God. At the same time, the Father is not the Son or the Holy Spirit, the Son is not the Father or the Holy Spirit, and the Spirit is not the Father or the Son. They are distinct from one another, yet they are God who is One, and none of them are forces or powers or influences or any such thing. Jesus clearly said in the Scriptures that He and the Father are one, and that he who has seen Him has seen the Father.

As you can see, God as three in one is not easily described in human terms and the best "description" I have found is that given in the last paragraph. 1 John 2:4 says,

"God is a Spirit: and they that worship him must worship him in spirit and in truth."

Genesis 1:1,26 gives the witness of Scripture that God is an "us" yet spoken of as one God:

Gen 1:1 In the beginning God created the heaven and the earth. . . .
26 And God said, Let us make man in OUR image, after OUR likeness:

In the New Testament, 1 John 5:7 makes this very clear:

1 John 5:7 For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one.

And Paul, in his letter to the Galatians, speaks of the three in the Godhead:

Galatians 4:4 But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law,
5 To redeem them that were under the law, that we might receive the adoption of sons.
6 And because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father.

Another example of Scripture speaking of God as three in One is written in Matthew 3:16-17 where the Son has just been baptized in the water by John, the Spirit of God descends like a dove, and the voice of the Father is heard from Heaven. This is an undisputable manifestation of the Trinity:

Matthew 3:16 And Jesus, when he was baptized, went up straightway out of the water: and, lo, the heavens were opened unto him, and he saw the Spirit of God descending like a dove, and lighting upon him:
17 And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased.

Lest we go off into error thinking that we are speaking of three Gods, let us be reminded with these verses that God is One, not three Gods:

Deuteronomy 6:4 Hear, O Israel: The LORD our God is one LORD:
5 And thou shalt love the LORD thy God with all thine heart, and with all thy soul, and with all thy might.

The One God has revealed Himself to us as three distinct Persons and each of them is fully God, yet distinct from one another. Can we in our fallen condition fully comprehend God as three in one? No, for Scripture says,

1 Corinthians 13:12 says, "We see through a glass darkly; we know in part;...but now abideth faith..."

But be reminded that the Apostle Paul wrote,

1 John 3:2 Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when he shall appear, we shall be like him; for we shall see him as he is.

For now, know that

Colossians 2:9 For in him dwelleth all the fulness of the Godhead bodily.
10 And ye are complete in him, which is the head of all principality and power: