From Wayne Grudem’s Systematic Theology (1994):

Thus, we should not think of God as having size or dimensions even infinite ones (see the discussion on God’s omnipresence in the previous chapter). We should not think of God’s existence as spirit as meaning that God is infinitely large, for example, for it is not part of God but all of God that is in every point of space (see Ps. 139:7–10). Nor should we think that God’s existence as spirit means that God is infinitely small, for no place in the universe can surround him or contain him (see 1 Kings 8:27). Thus, God’s being cannot be rightly thought of in terms of space, however we may understand his existence as “spirit.”