Isaiah 20 provides a striking account of the willingness of a servant of God to do His will:
Isa 20:1 In the year that Tartan came unto Ashdod, (when Sargon the king of Assyria sent him,) and fought against Ashdod, and took it;
2 At the same time spake the LORD by Isaiah the son of Amoz, saying, Go and loose the sackcloth from off thy loins, and put off thy shoe from thy foot. And he did so, walking naked and barefoot.
God spoke to His servant, Isaiah, to walk around naked and barefoot! Was Isaiah, in fact, actually required by God to be naked to in his service to God? The following verses explain the remarkable dedication that he had to have at this time:
Isa 20:3 And the LORD said, Like as my servant Isaiah hath walked naked and barefoot three years for a sign and wonder upon Egypt and upon Ethiopia;
4 So shall the king of Assyria lead away the Egyptians prisoners, and the Ethiopians captives, young and old, naked and barefoot, even with their buttocks uncovered, to the shame of Egypt.
That Isaiah’s service to God involved actual nakedness at least to some extent is made clear by the comparison that the Lord makes (“Like . . . So . . .” [20:3-4]) between what he did for three years (20:3) and what would happen to the Egyptians and the Ethiopians who would be taken captive by the king of Assyria—they would go into captivity “even with their buttocks uncovered” (20:4) to their shame!
Noting the extremely humiliating nature of the service that God called Isaiah to render to Him should challenge us to do readily whatever God may call us to do for Him, even though it may be quite challenging in various ways.
 “For three years Isaiah did not wear his outer garment of sackcloth (also the attire of Elijah, 2 Kings 1:8), or his sandals. (He was not completely naked.)” (John A. Martin, BKC: OT, 1067; emphasis in original). “Isaiah is to walk about partially naked and barefoot, v. 2.” (Peter A. Steveson, A Commentary on Isaiah, 167).