So how should we treat it then? Harmful? Please explain how, specifically, the Adventist denomination has harmed people. While you are at it, you'll be able to offer some specific examples how the Adventist Church is unbiblical right? As i said, it's easy to make sweeping generalisations and quote a heap of long tired rumours about plagiarism and money making. But not so easy to honestly discuss actual Bible teachings.
Yes, Adventism is harmful, and your attempt to dismiss every correction as rumor is exactly how false systems protect themselves from Scripture.
The investigative judgment is not taught anywhere in the Bible. Christ did not begin reviewing believers in 1844. Jesus said, “It is finished” ~John 19:30. Scripture says, “By one offering he hath perfected for ever them that are sanctified” ~Hebrews 10:14. The believer “shall not come into condemnation; but is passed from death unto life” ~John 5:24. Adventism clouds the finished work of Christ with a doctrine invented to rescue a failed prophecy.
Then there is Ellen White. Calling her writings a continuing source of instruction and correction gives an extra-biblical voice authority over the church. Scripture already makes the man of God “throughly furnished unto all good works” ~2 Timothy 3:16-17. If Scripture fully furnishes us, Ellen White adds nothing necessary. If she adds necessary light, then Scripture was not sufficient. You cannot have it both ways.
Adventism also turns the seventh-day Sabbath into a badge of faithfulness and ties it to end-time loyalty. Yet God says, “Let no man therefore judge you...in respect of...the sabbath days: Which are a shadow of things to come; but the body is of Christ” ~Colossians 2:16-17. You are defending the shadow after Christ has come.
That is the harm. It burdens consciences, weakens assurance, elevates a false prophetic authority, and places believers under religious requirements the apostles never imposed upon the church.
You asked for Bible teaching. There it is. Stop demanding evidence and then waving it away because it condemns your denomination. “Let God be true, but every man a liar” ~Romans 3:4.
Your loyalty is showing. You are not testing Adventism by Scripture. You are twisting Scripture to protect Adventism. Repent before your denomination becomes more precious to you than the truth of God.