Amos 5:25

Have ye offered unto me sacrifices and offerings in the wilderness forty years, O house of Israel?

Amos 5:25 belongs to the warning that called Israel to return, confronting the people with sin, righteousness, and judgment and giving individuals opportunity to repent before national punishment and chastisement. Through the forty years in the wilderness Israel neglected the appointed sacrifices and did not truly offer them to God, abandoning the appointed Levitical sacrifices from the very time of their institution. The disloyalty began even while Moses was on Sinai, when the people grew disloyal to him and still more disloyal to God, dismissing him as this Moses who had gone they knew not where to an unknown place.

While keeping up outward sacrifices and offerings, the people held fast to secret and self-excused sin and also worshiped the host of heaven and other idols they had made for themselves. These included the tabernacle of Moloch and the images of Chion and the star of the god and the star of Remphan and figures representing the heavenly bodies, holding that false tabernacle dearer than the tabernacle of Witness and the tabernacle of witness and the presence of God. Because they refused to worship God, he gave them over to that idolatry, which is linked to being taken into captivity beyond Damascus.

Elaborate worship without just and faithful conduct in life does not please God but insults him, and the offerings of such worshipers are not accepted and are an abomination to him. Indulging even one known sin while confessing many others shows insincerity, makes a mock of divine jealousy and of God's holy jealousy, and cuts the worshiper off from mercy, so that holding to some sins or even one sin prevents forgiveness of all other sins. In Acts Stephen uses this wilderness history to show that Israel resisted God and followed false worship even after receiving his guidance.