Holy week is not stated in the bible for Christians to observe. While it records the suffering, death, burial, and resurrection of Jesus Christ as the foundation of the Christian faith, it does not instruct believers to commemorate these events through a special annual week of religious observances. As children of God we are called to always remember the suffering of Jesus Christ and always keep ourselves holy.
Rather than focusing on traditions established later in history, the Bible emphasizes living a holy life every day and following the teachings of Jesus Christ. Remembering His sacrifice is essential, but true biblical worship is shown through sincere faith, repentance, love, and obedience to God's will throughout the year, not only during a particular season.