Even though the term "holiness" appears 900 times in scripture, God's people struggle to understand it. The first time it appears in scripture is God's appearance at the burning bush (Exodus 3) when the ground became holy because of God's presence, just as when the Commander of God's Army met Joshua. The principle of sanctification applies to time as well as place, as God sanctified the seventh day Sabbath as a covenant sign between Him and His people (Ezekiel 20:12) as a "test commandment" of obedience. We keep the Sabbath when we cease from ordinary work, gather in holy convocation, rest, focus on God, and appreciate the day of delight (Isaiah 58:13-14) a day designed for rest, worship, and spiritual growth (Mark 2:27). Holiness demands both inner humility and outward reverence. As Moses removed his sandals, God's people must surrender pride, show respect, and walk in obedience, maintaining holiness in all their conduct (I Peter 1:15-16).