God was not playing! Aaron's sons just died because they offered the wrong thing to God and God decides this is a good time to let Aaron know some things about the innermost part of the tabernacle- the most holy place.
Now the first thing that drew my attention was the fact that God spoke, not to Aaron, but to Moses, who had to relay the message to Aaron. Aaron was a minister in the house of the Lord, as well as Moses' brother, but he was subject to the Word of the Lord that came through Moses.
Pastor Moses was over the church called Israel- and like today's Pastors, Moses was responsible for relaying the Word of God to Aaron; otherwise, that transgression- in this case entering the Most holy place unworthily- would be on his head. Hebrews 13:17 admonishes us to submit to our spiritual leaders' authority as they keep watch over us as men who must give an account. SO even though we may think , hey i have a better idea, or hey, they're not the only one God speaks to: true, but we are still required to submit to the authority of God that he manifests through the spiritual leader- our pastors.
That being said, going beyond the veil into the most holy place required great attention to detail. God wanted his orders to be carried out with great diligence. It may look as if God is an overly-demanding or tyrannical God.
I remember at age 16 writing a list of requirements that my future husband had to meet. Now no one was going to die, had they not met the requirements- well, who knows.
From a spiritual point of view , we see that God is not so much demanding, just care-ful.
He is a precise God with a precise plan. This should bring us comfort in knowing that this same God, if he is lord of our lives , has everything under control- he knows what he is doing.
And who else would be better at saying how to approach God besides God?
A certain calling, a cleansing had to be performed and the garments had to be just right- to enter beyond the veil. If one thing was out of place, it meant death, for the priest.
We are proclaimed to be a royal priesthood, according to Peter ( 1 Peter 2:9). We are now able to go beyond the veil for ourselves, and our families- standing in the gap and acting as bridge between the carnality of the flesh and realm of the spirit.
Not just anyone can be a part of the royal priesthood- it requires the cleansing ( John 3:5) and putting on of the priestly garments. The priestly garments included, a robe, a head covering, a belt, a breastplate; all seemingly synonymous with the helmet of salvation, the belt of truth, the breastplate of righteousness. It requires being called out, just as the levites were called out and set apart. Our word church, comes from the greek word Ekklesia - meaning the called out ones, and God requires his church to be holy, set apart , as he is holy.
See how we fulfill the priestly requirements? All dilligence must be given to our purity and what we are clothed in- whether robes of God's own righteousness, or robes of our flesh; we have to meet the conditions to get beyond the veil, and enter into holy communion with Jesus Christ.
9And be found in him, not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith:
10That I may know him, and the power of his resurrection, and the fellowship of his sufferings, being made conformable unto his death;
11If by any means I might attain unto the resurrection of the dead. (Philippians 3:9-11, King James Version)