Innovation (Bidah)
Bidah is an Arabic word that comes from the root Al-Bada’ meaning to create something without precedence. In English we would use the word innovation. Before discussing bidah in any depth we must distinguish between two types of bidah. The first type is innovation in the matter of things pertaining to our worldly life. Things like technology, electricity and transport would come under this category. These things are permissible and in many cases could even be called desirable. The second type of innovation pertains to matters of the deen. In matters of religion bidah is not permissible and it can be dangerous to introduce new things in our religion. Because of the danger there are many quotations and traditions from the Sunnah of Prophet Muhammad that point this out.
“Whoever innovates into this affair of ours something that we have not commanded, it is to be rejected“. [Saheeh Bukhari, Saheeh Muslim] “The best speech is the Book of Allah and the best guidance and example is that of Muhammad, and the worse of all things are the newly invented things (in the religion), for every innovation is an error and a misguidance“. [Saheeh Muslim] “…Every innovation is a going astray and every going astray is in the fire.”[At Tirmidhi]
Shirk 
The Arabic word shirk is the opposite of tawheed, Allah's oneness and uniqueness, and is more inclusive than polytheism and idolatry. Shirk contradicts the very purpose of creation as expressed in the Quran:
"I have not created jinn or mankind except to worship Me." (Quran 51:56)
Prophets were sent with the mission to eradicate shirk and to invite humanity to single out Allah in worship.
What is Shirk?
Shirk is to associate someone other than Allah in those aspects which are unique to Allah and His exclusive right. Shirk is to worship created beings like Allah is worshipped, to venerate created beings like Allah must be venerated, and to assign a portion of His divinity to someone else.
Severity of Shirk !
There is no issue upon which Islam is so strict as the one of tawheed (monotheism). Therefore, shirk is considered the greatest violation with which the Lord of the heavens and the earth is defied. The severity of shirk can be summarized in the following points:
The Islamic Ruling on Horoscopes
Not only is the practice of astrology Haraam, but also visiting an astrologer and listening to his predictions, buying books on astrology or reading one’s horoscope are also forbidden. Since astrology is mainly used to predicting the future, those who practice it are considered fortunetellers. Consequently, one who seeks his horoscope comes under the ruling contained in the Prophet’s sallallaahu ‘alayhi wa sallam statement:
"The Salaah (daily prayer) of whoever approaches a fortuneteller and asks him about anything will not be accepted for forty days and nights." [Saheeh Muslim vol.4,p. 1211, no 5440]
The punishment in this hadith is simply for approaching the asking the astrologer, even if one is in doubt about the truth of his statements. If one is in doubt about the truth or falsehood of astrological information, he is in doubt about whether or not others know the unseen and the future besides Allaah. This is a form of shirk because Allaah clearly stated:
“And with Him are the keys of ghayb [all that is hidden], none knows them but He and He knows whatever there is in [or on) the earth and the sea; not a leaf falls, but the knows it. There is not a grain in darkness of the earth nor anything fresh or day, but is written in a clear record." [6:59]
Charms and Amulets
For thousands of years people have tried to bring good luck and avert bad luck from them and their property by employing charms, amulets, and talismans.
A charm is a practice or expression believed to have magic power, similar to an incantation or a spell.[1] A talisman is an object bearing a sign or engraved character, and thought to act as a charm to avert evil and bring good fortune.[2] Amulets were used to protect man, or his possessions, such as houses and cattle from the evil influences of witches, demons, and other mischievous powers, or to counteract misfortune and illness. The amulet is found both in the Orient and in the West, among tribes and nations down to the present day. Assyrians and Egyptians, Greeks and Romans, Jews and Christians, fostered this ancient superstition, and, in varying degrees, foster it today.[3] Despite technical and scientific advancements, superstitions and amulets continue to pervade the Western society.
Some of the amulets popular in the West are:
Sects and Islam
While the majority of Muslims share the same fundamental beliefs, with 1.7 billion adherents –close to a quarter of planet Earth's population distributed over the far stretches of the continents and among 49 countries where Muslims are a majority and a history of more than a thousand years, all people who call themselves Muslims are not exactly the same. There are sometimes significant religious differences between them.
Does the existence of sects mean that Islamic teachings (contained in Quran and Sunnah) mandate them? The answer is no. What is important is to realize that unlike other religions, Allah has taken upon Himself to protect Islam - the last revelation and the most complete religion of God to humanity. You will not find any promise from God in the Bible or almost any other religious text that He will protect it. On the other hand, you do find two important promises from God in the Quran:
"God has completed His religion of Islam" (Quran 5:3) God will protect and safeguard His religion form change (Quran 15:9)