The Gospel is not complicated at it's core. Accept the sacrifice of Jesus, allow Him to bridge the gap between us and God, and be reconciled with our Heavenly Father through Him. And only Him.
Paul mentions things leading us away in 2 Corinthians 11. He talks about us needing to be cautious if someone comes teaching something other than the Gospel we first received. That thought is my basis for my concerns over the "Progressive" movement. It dilutes the Gospel I first received and mixes it with other religious systems. It denies things the Bible calls Sin and deems that we "enlightened" people of the 21st Century know better than the Apostles and Prophets.
At it's core, Christianity is a very simple Faith. Living a Christian life is harder when bombarded by the constant list of rules and regulations men have added to Jesus' teachings. The trick is to go beneath the 2000 years of rubble and dogma that have been piled on the core message of the Gospel.
Firstly, the Gospel is Good News. Literally. The word has been transliterated to English, but actually means "Good News". Jesus spoke simple truths to the people of His day. He didn't come in Judgement - that will only come on the Last Day according to the Bible. He came for a mission. He told us what it was in Luke 4:18-21
because he has anointed me
to proclaim good news to the poor.
He has sent me to proclaim freedom for the prisoners
and recovery of sight for the blind,
to set the oppressed free,
to proclaim the year of the Lord’s favor.”
Your $20,000 car or $100,000 house doesn't become worth nothing once you've made the last payment. It's still worth $20,000 if you pay cash on the day. A Stradivarius Violin isn't worthless because it was paid for. Sin's price has been paid, but it's still sin. Jesus forgave the woman caught in adultery (notice it doesn't specify the gender of the other person), but rather "Jesus straightened up and asked her, “Woman, where are they? Has no one condemned you?” “No one, sir,” she said. “Then neither do I condemn you,” Jesus declared. “Go now and leave your life of sin.”"
"Leave your life of sin". The phrase speaks through the ages. She's not condemed, but forgiven. Yet Jesus tells her to stop living a sinful life. Whether the co-adulterer not brought out was a man or another woman, Jesus doesn't ask because it doesn't matter. The fact is that sin is sin, irrespective of who you sin with. He says stop.
He doesn't say "I forgive you, go and continue as you were."
He says "Leave your life of sin"
No ambiguity. No details asked or offered. What He effectively is saying is "You know what you're doing is wrong. I know what you're doing is wrong. Stop doing it!"
We mustn't reclassify behaviour as no longer a sin because of modern "wisdom", specifically because God's wisdom is foolishness to men. If God is the same yesterday, today and for ever, then surely His definition of sin is as well. And we don't have the right to try to change that.
And I'm not only talking about sex here.
Greed, selfishness, idolatry and all the others in Genesis to Revelation are more rampant today than ever in history. But we ignore most of them. "Greed" gets relabelled as "Success", "Selfishness" as "ambition", "Idolatry" as "Respect" and then ignored.
Be not deceived, God is not to be mocked. Or taken lightly.
But we do. We recreate God in the sanitised version we'd like. Remove all hints of true Justice and as Dorothy L Sayers put it "Pare the claws of the Lion of Judah". Pull His teeth. Make Him less so He fits in the box we want for Him. Then tell everyone He's not in a box (unless it's ours, then it's ok).
We do this at our peril. If we try to change God to fit our wants, we shatter who and what He truly is. Present tense. We are not qualified to judge God's opinion of what is and is not sinful. He is a Righteous God, and any unrighteousness is abhorrent to Him now, just as it was 2000BC. Just as it will be in 2000 years if He waits that long.
The fact that one known "Progressive Christian" describes the movement as taking "the Bible seriously but not necessarily literally, embracing a more interpretive, metaphorical understanding; emphasizes orthopraxy instead of orthodoxy (right actions over right beliefs); embraces reason as well as paradox and mystery -- instead of blind allegiance to rigid doctrines and dogmas; does not consider homosexuality to be sinful; and does not claim that Christianity is the only valid or viable way to connect to God (is non-exclusive)" (Kissing Fish: Roger Wolsey) demonstrates a clear deviation from what Paul wrote and Jesus taught in the New Testament. It also deviates from what the Law taught in the Old Testament. If Christianity through Judaism were not the only valid or viable way to connect with God, why then was the slaughter of anyone who worshipped Baal necessary? Why eliminate the entire population of what became the territories of Israel? Why not just move in and coexist?
Why destroy Sodom and Gomorrah? I'm sure a "progressive" response would indicate this was a metaphor or a myth or a moralistic fiction, but then why mention it at all if their behaviour was not sinful and didn't block relationship or right standing with God?
The "Progressive Christianity" concept of (as Wolsey puts it) leaning towards panentheism and inclusiveness with an emphasis more on right actions than right beliefs is dangerous ground. It promotes salvation by works rather than Grace, universalism not Christ as the one way to God and condemns people who call a sin a sin, especially if that sin is homosexual behaviour. Right actions come from a place of right beliefs, they don't lead to it.
True Christianity by comparison teaches Salvation by Grace through Jesus, "For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast. For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand that we should walk in them." (Ephesians 2:8-10) The social justice, environmentalism and non-violence these "progressive" beliefs claim as their own should flow naturally from True Christianity. John 14:15 says "If you [really] love me you will keep (obey) my commands" (Amplified). The inferrence is that keeping Jesus' commands flows out of loving Him. The concept of signs and wonders following the believer confirms this. First comes the relationship, and the works are borne out from there. Faith produces action. Without works, Faith is dead as James puts it. But Faith will produce action - action will not produce Faith.
So finally I'll try to leave the concept of "Progressive" changes to Christianity alone. Anything other than the Gospel we received when we first were saved should be discounted and rejected. So says St Paul. The social stance may be admirable, but the "evolution" of what this sect teaches moves away from the Jesus of the Gospels and the God of the Bible. They are welcome to the term "progressive" while it means "conforming to the pattern of the world", which every explanation of their beliefs indicates.
Personally, I'll look to the renewing of my mind, and the Godly Transformation the Bible promises with it.