In one sense the doctrine of the trinity is a mystery that we will never understand fully.

Sin is any failure to conform to the moral law of God in act, attitude, or nature

The clarity of Scripture means that the Bible is written in such a way that its teachings are able to be understood by all who will read it seeking God's help and being willing to follow it.

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.

God's faithfulness means that God will always do what He said and fulfill what He has promised.

Satan was the originator of sin