Aaron had four sons: Nadab, Abihu, Eleazar, and Ithamar. Nadab and Abihu were the older two and, like all good sons, they were training to go into the family business. They must have shown promise, because the Lord invited them to come along with the elders of Israel for the feast on Mount Sinai. One can imagine how getting an invitation to have supper with God Almighty might cause one to become a little prideful.
After bringing us into covenant with Him by cleansing us with His blood, the Lord leads us to a life of consecration. The longer we walk with the Lord, the more He challenges us to let go of the world. Activities we enjoyed without guilt in the past now become restricted by convictions. But with each conviction followed comes a new liberty to serve the Lord in consecrated holiness.