from here: https://www.str.org/w/live-according-to-a-plumb-line-not-a-pendulum

Live According to a Plumb Line, Not a Pendulum

AUTHORAlan ShlemonPUBLISHED ON03/02/2021

You may have heard the stories. Sadly, it’s a pattern many Christians follow. A believer grows up with a misconception about the Christian worldview. One day, he discovers the truth and realizes he was mistaken. He becomes disillusioned with his faith and reacts by adopting a completely opposite—but also unbiblical—position. We often say the pendulum swung the other way. He went from one extreme to the next. Both positions, however, are wrong.

Examples abound. A girl who was raised in a “fundamentalist Christian home” was told Muslims are the enemy and dangerous people. When she went to high school, she met Saeed, a friendly Muslim in her class. Saeed was kind, chivalrous, and respectful of her Christian faith. All of her preconceived notions were destroyed. Saeed was nothing like the way her parents had characterized Muslims. Eventually, she began dating him, they fell in love, and she converted to Islam. The pendulum swung the other way.

In another example, a family was attending a conservative church in the Bible Belt. “Homosexuality is sin” was drummed into their heads. It was as if the church disproportionately singled out the sin of homosexuality as one of the most grievous sins. When the son reached high school age, he told his parents he was gay. Disillusioned, the parents looked for answers by scouring the internet and asking their friends for support. They came across Matthew Vines’s book, God and the Gay Christian, a book that supports the idea that one can be gay (e.g., have a same-sex lover, marry someone of the same sex, etc.) and be a faithful Christian. The parents were relieved to discover this “option” and fully embraced pro-gay theology. The pendulum swung the other way.

I’ve also heard multiple testimonies of progressive Christians explaining how they rejected the legalistic Christian “fundamentalism” of their youth and now hold more “reasonable” positions like being pro-choice, pro-gay, and claiming Jesus was a socialist. The pendulum swung the other way.

There’s a similar pattern repeating itself. A Christian becomes aware of an error in their faith but then overcorrects by adopting a view on the other end of the spectrum. The pendulum swings to a position that’s opposite of their starting point but still wrong in a different way.

Scripture offers a better and more accurate approach to gauge our spiritual life and discover what our position should be on any matter: a plumb line. A plumb line is a builder’s tool. It consists of a heavy, pointed weight attached to a string. Gravity makes the string hang perfectly straight (or plumb), giving a builder a vertical line by which to build a structure.

Scripture uses a plumb line as a metaphor for spiritual truth by which we can align our lives. For example, God tells Isaiah, “I will make justice the measuring line and righteousness the plumb line” (Isaiah 28:17). God also sends the prophet Amos to warn Israel of impending judgment because of their disobedience:

The Lord was standing by a vertical wall with a plumb line in His hand. The Lord said to me, “What do you see, Amos?” And I said, “A plumb line.” Then the Lord said, “Behold I am about to put a plumb line in the midst of My people Israel. I will spare them no longer.” (Amos 7:7–8)

The plumb line makes it clear to God’s people how far they’ve strayed from his perfect will.

The mistake is to follow the swing of a pendulum rather than adjust your position according to a plumb line. The problem with swinging the pendulum the other way is that it mistakenly presumes that the opposite position of an incorrect view is always correct. It can be, but that isn’t always the case. When you realize you’re in error, the biblical approach is to look at Scripture like a plumb line and realign your view according to that unchanging standard.

Had the people in my previous examples heeded this advice, they’d still be faithful Christians. The girl wouldn’t have become a Muslim, but she would recognize that that no person—even a Muslim—is your enemy; they’re a valuable image-bearer of God who needs a pardon. Rather than adopting pro-gay theology, the parents would have simply embraced Jesus’ sexual ethic while unconditionally loving their son. The progressive Christians would have jettisoned their theological error and adopted a more biblical view.

The proper corrective in these cases is to align your views to the plumb line of Scripture. That’s why God has given it to us. It’s for our good and for the health the church.