I think this is true for all Christians, including Catholic and Orthodox Christians too. We all know in part, and do not read the Scriptures without personal bias. You come to the Bible with Catholic preconceived notions. I come to the Bible with Calvinistic glasses. We all see dimly. If you think about it, God the Holy Spirit illuminates truth to us through opening up the Scriptures to us. So, in the flesh without the Spirit, we are not able to understand the Scriptures correctly. The Catholic Church does change all the time, even though she does not admit it. New confessions and catechisms, and pronouncements are added all the time. I am a staunch Calvinist Christian posting two Catholic links on my signature which I consider to be highly profitable for all Christians. Therefore, something has changed. Did you struggle with the teaching of justification by faith as a Catholic?