From The Life and Times of Bruce Gerencser:
One common refrain often heard in some corners of the Evangelical world goes something like this: Praise God, I have NEVER changed my beliefs. I am seventy years old and I still have the exact same beliefs I had at age twenty — fifty years ago. There is this idea floating on the backwaters of Evangelicalism that posits that change is bad, or even sinful. Pastors and congregants pride themselves in having held the one true faith their entire life, that their Christology, soteriology, ecclesiology, eschatology, rheumatology, and hamartiology is the same yesterday, today, and forever. These theological purists will also say that their behavior hasn’t changed either. The sins they were against in the 1970s are the same sins they oppose today. These “just like a tree planted by the waters, I shall not be moved” Christians believe that they love what God loves and hate what God hates; that their interpretations of the sixty-six books of the inspired, inerrant, infallible Christian Bible align closely with God’s mind; that thanks to the Holy Spirit living inside of them as their teacher and guide, they are spiritually mature people who feast on the meat of the Word of God, not the pablum most Christians eat. (1 Corinthians 3:1-3 and Hebrews 5:11-13)
In most spheres of life, learning new things and discarding old beliefs, practices, and ideas is desired and expected. Not in Evangelicalism.