At the same time, by their sins the Jews were separating from God. They were unable to discern the spiritual meaning of their symbolic services. In self-righteousness they trusted their own works—the sacrifices themselves—instead of relying on the merits of Him to whom these things pointed. “Seeking to establish their own righteousness” (Romans 10:3), they built up a self-sufficient system of forms. Not content with the regulations God Himself had appointed, they invented countless detailed rules of their own. The greater their distance from God, the more rigorously they observed these forms. RR 248.7
With all these burdensome rules it was practically impossible for the people to keep the law. The glorious truths shadowed in the symbolic services were buried under a mountain of human tradition. Those who really wanted to serve God groaned under a heavy burden. RR 249.1