It is scripture alone, not conservative Evangelical tradition or any other human authority, that must function as the normative authority for the definition of what we should believe. The authority of the scripture means that all the words in scripture are God's words in such a way that to disbelieve or disobey any word of scripture is to disbelieve or disobey God.

The devil's characteristic has been to originate sin and tempt others to sin

God eternally exists as three persons, Father, Son and Holy Spirit, and each person is fully God, and there is one God.

Satan was the originator of sin

God fully knows himself and all things actual and possible in one simple and eternal act.

The idea that all the words in Scripture are God's words in such a way that to disbelieve or disobey any word of Scripture is to disbelieve or disobey God.

If God is not unchanging, then the whole basis of our faith begins to fall apart, and our understanding of the universe begins to unravel. This is because our faith and hope and knowledge all ultimately depend on a person who is infinitely worthy of trust - because he is absolutely and eternally unchanging in his being, perfections, purposes, and promises.