"For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one."
"In the beginning was the Word, and the Word was with God, and the Word was God." -John 1:1 KJV
"And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth." -John 1:14 KJV
Here is what Jesus says about His relationship with His Father: "I and my Father are one." -John 10:30 KJV
"...the Father is in me, and I in him." -John 10:38 KJV
When Jesus was ask by the Pharisees where His father was, He said, "...if ye had known me, ye should have known my Father also." -John 8:19 KJV
The Holy Spirit is often described as the Spirit of God. "...And the Spirit of God moved upon the face of the waters." -Genesis 1:2 KJV
In Matthew 3:16, the Spirit of God descended on Jesus as soon as He was Baptized. In Luke 3:22, it is described as the Holy Ghost descending on Jesus. While this was happening, the verse describes the Father speaking from Heaven declaring Jesus as His son whom He is well pleased. So, here you have the Father, the Son, and the Holy Spirit at the same time.