Nehemiah 9:35
For they have not served thee in their kingdom, and in thy great goodness that thou gavest them, and in the large and fat land which thou gavest before them, neither turned they from their wicked works. For they have not served thee in their kingdom, and in thy great goodness that thou gavest them, and in the large and fat land which thou gavest before them, neither turned they from their wicked works.
It belongs to Israel's confession of sin and plea for pardon, made when God's law was explained so the people could understand it and sealed as a sure covenant. The confession charges all ranks with failure, that neither kings, princes, priests, prophets, fathers nor the people kept the law nor hearkened to the commandments and testimonies. Even while ruling in their own kingdom and receiving God's great goodness and the large and fat fertile land given before them, they did not serve Him, not with singleness of purpose, and did not turn from their wicked works and ways but corrupted their ways and turned from Him. That failure to serve despite goodness and abundance is the same unfaithfulness John later hoped his preaching would lead Israel to repent of and return from.
Intermarriage with other nations and the resulting corruption of the Hebrew language stand as evidence of that sin. Those sins separated them from God, and He would not serve with their sins. He is just in all the trouble, distress and foreign dominion that came upon them, permitting them to be brought under the control of heathen nations. God therefore does not work through those who refuse to serve Him, but honors those who honor Him, working instead through a faithful man like Nehemiah.
That confession and sure covenant is to be presented to the people as occasion requires, calling those in positions of influence to decided reformation so they can stand boldly in defense of the truth against its increasing perversion into evil. The verse applies to Seventh-day Adventists, who despite receiving great truths and evidences of God's favor have not sufficiently valued His gifts or returned the glory due His name.