Numbers 3:4: "Nadab and Abihu had died before the Lord when they offered profane fire before the lord in the Wilderness of Sinai; and they had no children. So Eleazer and Ithamar ministered as priests in the presence of Aaron their father.
The sin of Nadab and Abihu was a manifold one,
(a) they each took his own censor and not the sacred utensil of the sanctuary;
(b) they offered it together, whereas incense was only to be offered by one;
(c) they presumptuously encroached upon the functions of the high priest; for according to the Law the high priest alone burnt incense in a censer;
(d) they offered incense at an unauthorized time, since it was apart from the morning and evening sacrifice. The operative phrase in the incident is "profane fire" ("profane" here has the force of "unlawful" or "common"). The presumptuous priests committed sacrilege by filling their vessels with common fire instead of taking it from the holy fire of the altar, which was always to be used in the burning of incense.
This is a word of considerable relevance today, when the need for new, modern methods in "getting out the gospel" to our generation is repeatedly emphasized. We need to be aware lest a question of methodology become one of theology. It is easy to stray from the divine order through a desire for innovation, for innovation's sake, and thereby lose contact with the divine fire which alone can give true inspiration.
James Denny, in a sermon titled "Wrong Roads to the Kingdom" wrote:
There is always a tendency in the Church to trust methods which appeal to the senses than to the soul, of which are believed to be reaching the soul though they never get past the senses....The trust of the Church in other things is really a distrust of the truth, an unwillingness to believe that its power lies in itself, a desire to have something more irrestistible than truth to plead truth's cause..
Of which all these methods are modes of athiesm. God, Jesus, the power of the Spirit, and His word are our real source...and therein in is the "method" we ought to use.