For they provoked [Moses’] spirit, so that he spoke unadvisedly with his lips.
34 They did not destroy the [heathen] nations as the Lord commanded them,
35 But mingled themselves with the [idolatrous] nations and learned their ways and works
36 And served their idols, which were a snare to them.
Psalm 106:33-36 (AMP)
And Nadab and Abihu, the sons of Aaron, each took his censer and put fire in it, and put incense on it, and offered strange and unholy fire before the Lord, as He had not commanded them.
2 And there came forth fire from before the Lord and killed them, and they died before the Lord.
3 Then Moses said to Aaron, This is what the Lord meant when He said, I [a][and My will, not their own] will be acknowledged as hallowed by those who come near Me, and before all the people I will be honored. And Aaron said nothing.
Leviticus 10:1-3 (AMP)
One of the major manifestations of mingling is modifying God’s Word/orders. It is not that we refuse outright, but we do it on our own terms – our time, our way, with whomever we choose. We try to please God our way instead of His.
It is a manifestation of pride to believe we are smarter than God and our plan is better than His, what arrogance! In Psalm 106, they disobeyed the Lord’s command to destroy the heathen nations, those nations in turn seduced them away from God.
In Leviticus 8, God instructed Moses to ordain Aaron and his sons into the priesthood, this ended with a 7-day retreat with the Lord. Chapter 9 ended on a high note with the glory of God appearing to the people and His fire consuming the sacrifice.
In the beginning of Leviticus 10, Nadab & Abihu (Aaron’s sons) offered strange, unholy, unauthorized fire before the Lord as He had not commanded them. Why? Were they trying to prove they were anointed too and didn’t have to wait for directives from their father, the High Priest? Were they looking for the praise of men? Did they want to ascribe God’s glory unto themselves? We really don’t know why they did this, but it was unacceptable to the Lord and His response was immediate.
“Then Moses said to Aaron, “This is what the Lord meant when he said, ‘I will show myself holy among those who approach me, and I will be glorified before all the people.’” And Aaron was speechless” (Leviticus 10:3 TLB)
God is God, yes He is our Father, and yes He loves us but He is still God and deserves our utmost reverence and obedience. We are soldiers in His army, a good soldier does not rewrite his orders, but carries out the orders received from his commanding officer.
Jesus when He was on the earth said “I assure you and most solemnly say to you, the Son can do nothing of Himself [of His own accord], unless it is something He sees the Father doing; for whatever things the Father does, the Son [in His turn] also does in the same way. (John 5:19 AMP)
Jesus is our example, we are to walk in His steps, since He fully obeyed the Father we must do no less.