JOEL - Here is the entire scripture you are refering to:

John 10:38
"But if I do, though ye believe not me, believe the works: that ye may know, and believe, that the Father [is] in me, and I in him."

Scriptures like this provide examples of how differently people interpret scripture. If you look at only the last part of it, many would take it as saying that Jesus and God the Father are the same person.
But if you look at the whole scripture and the text before and after, it is quite clear that Jesus is only saying that, even if you don't believe me(Jesus), then just look at how the Father is reflected in me because of the works I perform. Earlier in John 10:36, Jesus identified Himself as the Son of God. As such, one would expect Jesus to perform works similar to what His Father would do. "The Father [is] in me, and I in him" could also be said for any mortal man when you look at the similarity between what he would do compared to what his own father would do.

In John 8:19 we read,
"Then said they unto him, Where is thy Father? Jesus answered, Ye neither know me, nor my Father: if ye had known me, ye should have known my Father also."
Here it again sounds as if Jesus and the Father are the same person. But later in verse 38, Jesus equates His father/son relationship to that of mortal men when He tells His audience,
"I speak that which I have seen with my Father: and ye do that which ye have seen with your father."
He would not compare His relationship with His Father to the relationship of mortal fathers and sons if He and the Father were the same person.

Jesus also explained how the apostles should be "one" as He and the Father are one(John 17:11). If Jesus meant here that He and God the Father are one person, why would He tell His 12 apostles to do the physically impossible and become one person as well. He meant that they should be one in purpose as Jesus and His Father are.