Now, to do justice to Christianity, here is my take on "Christianity in a nutshell".
Christianity in a nutshell:
(First, I must state that my belief is non-trinitarian, trinitarian belief is (at least should be) identical, other than contesting a different understanding of God’s nature))
The Bible account: God exists always, with no beginning or end (requires faith, admittedly, and can’t be explained other than miraculously). True Christians are comfortable with speaking the truth- faith is required. Out of His goodness, He creates His only direct creation- His son. Through His son, He creates the universe and everything in it, both living and non-living, spirit and material, and pays particular attention to planet Earth. He creates Man, and then Woman, and gives them fatherly guidance as to how to be like Him, being good (immortal), and turning from evil, not being sinful in nature (mortal). Primary in this relationship of Creator and created beings is the principle of Headship.
One of God’s spirit creations, Lucifer, decides to disobey God’s headship, and he convinces Eve to disobey Adam’s headship, and she convinces Adam to disobey God’s headship. For this great disobedience, God banishes Adam and Eve from the garden of Eden, and, they now being sinful in nature, are mortal, facing a certain death at some point. Their life is no longer immortal. They pass this mortal, sinful nature on to their offspring. Likewise, Lucifer (now the Liar, Devil, Satan) and other spirit creations (angels, now demons due to their following Satan’s example of bucking God’s headship) are eventually banished from God’s presence.
This sets up the struggle that has taken place ever since. This struggle is between two diametrically opposed groups: Those who respect God’s headship, and endeavor to obey Him, and those who disrespect God’s headship, and endeavor to disobey Him. Those who side with God, and those who side with Satan.
God chooses humble men throughout history to be His servants. In a move that will prefigure His blessing of a group of people (true Christians) in the future, He chooses a humble man, Abram, and befriends him. He makes a covenant, a promise to him, that his offspring will be blessed as long as they obey God’s headship and follow his laws. God is true to His word, as He always is. Through Abram, who God renames Abraham, his son Isaac, his grandson Jacob, and his great grandson Joseph, who God renames Israel), God fulfils His promise. God is not partial, wherever people, whether Israelite or not, submit to His headship, and obey Him, he blesses them. Likewise, wherever people disobey Him, whether Israelite or gentile, he punishes them. In fact, on numerous occasions, God blesses other nations, rather than Israel, such as Egypt, Babylon, Assyria, Media, Persia, etc, because of Israel’s disobedience and these nations subjection to God. Every people that subject themselves to God and obey His laws he blesses, every people that do not subject themselves to God and disobey His laws he curses. The laws God gives ensure that people will know what is right and what is wrong. The sacrifices He demands remind people that they are sinful and need God’s redemption, because of what Adam and Eve wrought on their offspring (all humanity).
In order to perfectly fulfill His laws, and make one sacrifice to end all sacrifice, God chooses an Israelite woman, of the tribe of Judah, to carry in her womb His son, Jesus Christ. Now in human form, Christ proves who He is through His teachings, performs miraculous signs, and teaches and establishes a new covenant which fulfills the old covenant, taking its place as the means through which mankind may show their submission to God’s headship and be redeemed. He makes clear to all those living from then on, by His example, how mankind is to live. What we are to do, and what we are to avoid. He also makes clear that God has a day of judgment in store, in which each individual human and spirit creature will be judged by His son, Jesus Christ. Upon judgment, some creatures will be forever cut off from life, while others will receive life, living with Christ as their King for a thousand years, after which Christ will subject himself and all those living to God as their King.
These are the basic building blocks upon which all Christian theology is constructed. Atheists and others can protest that of course they don't really see things in such a simple and manifestly plausible way, but this narrative underpins what the Bible truly teaches.
BA- Understands that we all put faith in something. I choose to put my faith in God rather than men. Thank God!