Klaymen is no longer in the building, as it were, but I thought this particular statement should be addressed.
Actually, John 4:24 does not say "God is a Spirit." The English translation of John 4:24 says that, yes, but Greek does not have the indefinite article "a". Thus it could just as well have been rendered by the KJV translators as "God is Spirit." What does a translator want to say? If one is translating into English, and one is a Trinitarian, perhaps one might prefer to use the indefinite article "a" to make the doctrinal point of the incorporeality of God. Interestingly, in his German translation of the Bible, Martin Luther rendered this verse as "Gott ist Geist" ("God is Spirit"), omitting the indefinite article (which German does have) -- thus missing the opportunity to lend more support to the Trinitarian point that God doesn't have a body.
And then we come to the problem of being able to pray to God "in Spirit". Must we shed our body to pray to Him in truth? Or does "spirit" mean something more nuanced than incorporeality?
This is a good question. I am reminded of the 8th Article of Faith: "We believe the Bible to be the word of God as far as it is translated correctly..." But one might want to enhance the 8th Article of Faith as follows: "We believe the Bible to be the word of God as far as it is transmitted and translated correctly..."
Take 1 John 5:7-8, the Johannine Comma, for example.
7 For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one.
8 And there are three that bear witness in earth, the Spirit, and the water, and the blood: and these three agree in one.
These verses are very nicely supportive of the Trinity, as described in the Nicene Creed. As it turns out, they appear to be interpolations and not part of the original text. You can translate these two verses as correctly as you like, but are they the "word of God"? Their transmission is highly suspect and even if you believe the doctrine they imply, they must be excluded from canon, because they are not what flowed from the pen of the original writer. So, can we trust John 4?
I'm on mormondialogue.org (I'm Stargazer there), and he hasn't shown up there yet, so far as I can determine.