Compromise isn’t a sin. Compromising God’s Word may be sinful, though. It depends upon how you approach the subject.

It’s kind of hard to consider the question of sin since Christians can’t sin, though.
(Hebrews 8:10 NIV) This is the covenant I will make with the house of Israel after that time, declares the Lord. I will put my laws in their minds and write them on their hearts. I will be their God, and they will be my people.
(Hebrews 10:16 NIV) "This is the covenant I will make with them after that time, says the Lord. I will put my laws in their hearts, and I will write them on their minds."
We have God’s laws written in our hearts and our minds. How? The indwelling Holy Spirit is ever present to guide each of us into the path he has for us to follow.
Compromise isn’t a disease. If it’s a disease it can’t be a sin. Sin is something we do deliberately. Diseases afflict us without our approval.
I think I understand what you’re getting at but I’m not sure you’re presenting it in a way that makes your case.
(Psalms 119:11 NIV) I have hidden your word in my heart that I might not sin against you.
I think you’re saying that we need God’s word to guide us in the right direction. Yet, God’s pure word doesn’t actually exist. We trust that God’s word as we know it today has been put together via the guidance of the Holy Spirit.
(2 Timothy 3:16-17 NIV) All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, {17} so that the man of God may be thoroughly equipped for every good work.
There are multiple problems with this, though.
• We’re not reading the original languages the bible was written in.
• We’re trusting human beings in the church through the ages to determine which books belong in the bible.
• We’re not clearly familiar with the actual manners and customs of the biblical times.
• Religious Correctness and Traditions have clouded what we believe the bible actually says.
…just to name a few.

The pure Word of God comes straight from God. That’s why we need the Holy Spirit to speak to us and guide us on an individual basis.