Bible Study: What is strange fire?

Leviticus 10:1

And Nadab and Abihu, the sons of Aaron, took either of them his censer and put fire therein, and put incense thereon, and offered strange fire before the LORD, which he commanded them not.

1. Anyone that does a spiritual job that God has not ask you to do, is offering a strange fire.
2. For instance, if you start a church or Christian Ministry without the leading of the Holy Spirit, you are offering a strange fire
3. Strange fire can back fires; therefore don’t call yourself if God has not called you.