What the Quran teaches
Islam grew out of the Quran. To understand Islam it is therefore necessary first to understand the message of the Quran.
The Quran teaches God-consciousness or piety. It is important to develop God-consciousness for several reasons.
First, we should be thankful for the favours we receive from the Creator. It is only good manners to be grateful.
Second, God-consciousness helps us gain knowledge of the bigger picture and how we fit within the scheme of things. It makes it easier for us to follow guidance of the Quran.
Third, God-consciousness restrains man from committing sins and crimes, for a person knows that he or she will be accountable for all his or her actions on Judgment Day.
The Quran presents itself as an affirmation of the earlier revelations. The Quran teaches monotheism, that there is only one God.
It emphasises sincerity and censures hypocrisy. It counsels sharing and condemns stinginess. It warns of the Day of Judgment. It teaches that mankind was endowed with an excellent fitrah or nature.
The Quran teaches individual responsibility. The pious will have their reward in the Garden, while the wicked will be dwellers of the Fire.
It also teaches kindness to parents, strangers and orphans. It exhorts man to spend in the way of God. It teaches that human reason alone is insufficient to provide complete guidance to mankind.
The Quran relates many of the stories also told in the Old Testament, and a few from the New Testament.
What the Quran does not teach
The Quran does not teach death penalty for adultery or apostasy. These come from traditions attributed to the prophet. Neither does it teach that blasphemy is punishable by death. The latter has been extrapolated by the work of jurists.
[Disclaimer: Readers are advised to check the veracity of the statements made in this post for themselves. If any reader finds an error in this post, kindly inform me].