Commenting on John 4:24 and the phrase “God is Spirit,” Gary Burges noted the following in his volume on Pneumatology in Johannine literature:
Commentators agree that πνεῦμα ὁ θεός is not much so a Greek philosophical definition of who God is as it is a description of his dynamic attributes in relation to human beings. He is the God who gives the Spirit (14:16), and the Spirit in turn becomes the medium of his relation to human beings. Two similar descriptions in 1 John bear this sense: God is light (1:5) and God is love (4:8). This is how God acts in respect to the world. God gives the world light through his Son (3:19; 8:12; 9:5) as a tangible sign of his love (3:16). To say to a human being that God is Spirit is to say that their relationship must be a spiritual relationship. Because God is Spirit, human beings possess the Spirit. (Gary M. Burges, The Anointed Community: The Holy Spirit in the Johannine Tradition [Grand Rapids, Mich.: Eerdmans, 1987], 192)
Again, critics of Latter-day Saint theology who abuse John 4:24 against our theology of divine embodiment are guilty of eisegesis.