Nehemiah 9:17
And refused to obey, neither were mindful of thy wonders that thou didst among them; but hardened their necks, and in their rebellion appointed a captain to return to their bondage: but thou art a God ready to pardon, gracious and merciful, slow to anger, and of great kindness, and forsookest them not.
In its setting the verse belongs to Israel's confession of its history in Nehemiah 9, which repeats the Lord's works in behalf of His people and exposes their sins in turning from Him. The rebellion it describes meant refusing to obey, failing to remember God's wonders, hardening the neck, becoming stubborn, and in rebellion appointing a captain to return to bondage. That rebellion also included dealing proudly and making a molten calf and claiming it had brought them from Egypt.
The wonders they forgot were Christ's own work as their Redeemer, Protector, and wonder-working God, enshrouded in the pillar of cloud by day and pillar of fire by night to lead them. He divided the sea and destroyed their persecutors, led them by the pillars, spoke from Sinai giving right judgments, true laws, statutes and commandments and making known the holy Sabbath through Moses, gave bread from heaven and water from the rock, and promised the land. He gave His good Spirit to instruct them, and sustained them forty years so they lacked nothing with clothes not wearing out and feet not swelling. Against that disobedience the verse declares God's character: He is ready to pardon, gracious and merciful, slow to anger and of great kindness, and He did not forsake or abandon them in the wilderness.
His miracles did not save them because they would not obey His will and walk in obedience to it. When He came in person to their children He found the same rebellious spirit, because they did not have the love of God in them. Their sins separated them from God, so He permitted them to be brought under the control of heathen nations, demonstrating that He would not serve with their sins, and their punishment was just.
The leaders humbled themselves and confessed both their own sins and their people's sins and sought pardon as though they themselves had committed them. The people's acknowledgment of this history led them to covenant to obey God's law, preserve that commitment in writing, and avoid intermarriage with the people of the land. The same pattern applies to Seventh-day Adventists: though given precious truths and evidences of God's favor, they failed to value them and give God due glory, yet He did not wholly abandon them and heaven stood ready to support their worldwide work.