The physical universe is basically composed of matter, energy, space and time. The ancient Israelites practiced ritual worship based upon these 4 things. The matter was whatever items composed of matter that were used in the rituals, things like food, animals, tithes and sacrifices. Their time and energy was used constantly in the rituals. The space or place to perform the rituals was holy. What we see from all of this is a worship system that was totally physical repeated year after year. We should also know that this shadow type of worship is unacceptable to God. John 4:24 states the worship of God must be IN SPIRIT AND IN TRUTH. Spirit is not physical, mechanical or formalistic. It is from Our human spirit to Gods spirit with no physical thing involved. John 4:23 True worshippers will worship the Father in spirit and in truth. The Father seeks such as these to worship Him. Would it be correct then for us to invent practices that are clearly physical and try to worship God with them? There are indeed things people do that do just this thing. They borrow things from paganism and attempt to Christianize them by bringing God and Christ into them. God forbids this kind of practice in Deuteronomy 12:30. Jesus warned about adding traditions of men to the word of God. Christians should not practice the ways of the world for any reason. Keeping of physical days to worship God is incorrect thinking as scripture teaches. We must examine ourselves to see if we are worshipping God in the way Jesus instructed.