Hi.
Based on my readings, the practices described in Exodus are that of the Old Covenant–the Mosaic laws.
These have all been superceded by the perfection of the Old into the New Covenant of Christ. We still have a sacrifice (this time, a perfect one in Christ the Lamb). We still hold to the Ten Commandments. We have a new ordained, ministerial priesthood with the capacity to offer the One True Sacrifice to all of us. Many practices of the Mosaic law faded or were transformed into many traditions (small and large “T”) or incorporated into Canon Law in some way.
Most importantly, the New Covenant covers *all *people, not just the Israelites.