The Feasts that Yahweh gave Israel revolved around the yearly Harvests, which are a metaphor for His plan of Redemption and its unfolding (see Harvests Of Redemption). The feasts were specifically designated times (appointments) in the year to stop and look back at what Yahweh had done and to look forward to what He still would do. This is true today and His feasts still have these same purposes. The sacrificial system was terminated because Yahushua, the Christ, removed it. The principals remain and the plan of redemption continues to unfold.
This topic is currently unfinished and still under development