score:13
Good question.
God is a spirit as we are spirits—each human has a spirit residing within a mortal body. Likewise, Mormons believe God is a spirit residing within a perfected, glorified, and immortal body.
From lds.org:
The Greek text of John 4:24 contains no article before the word spirit. Thus, the Greek phrase can also be understood to mean “God is spirit,” or “God is spiritual.” The Apostle John also wrote that “God is light” (1 John 1:5) and “God is love” (1 John 4:8), but these statements do not mean that God is only light, or that God is love and nothing else. Neither do we understand the statement that “man is spirit” (D&C 93:33) to mean that man is only spirit and nothing else. In the same sense, John 4:24 does not mean that God is only spirit. From latter-day revelation, we know that “the Father has a body of flesh and bones as tangible as man’s; the Son also; but the Holy Ghost has not a body of flesh and bones, but is a personage of Spirit” (D&C 130:22).
In the context of the Savior’s teachings about true worship, the statement in John 4:24 can be seen as commentary more about the nature of worship than the nature of God. Since God is a spiritual being, people must worship Him “in spirit and in truth” (John 4:24), not merely through outward rituals performed at certain locations (see John 4:20–21). Introduction and Timeline for John 2–4