Why is correctness in doctrine important for Christians?

Sound doctrine is foundational for the Christian faith because it directs believers toward an accurate understanding of God's character and His redemptive plan through Christ. The Israelites' errors in worshiping both God and idols serve as a cautionary tale about the consequences of straying from correct beliefs. Mixing the old covenant with the new covenant, as addressed in the sermon, is not just doctrinally incorrect; it poses the risk of falling from grace. Thus, holding to the Five Solas and TULIP is essential for spiritual health and the manner in which believers relate to God. True salvation is entirely reliant upon the righteousness of Christ, and this must be well understood and taught.