Adhering to Tawheed (Islamic monotheism) does not only apply to deeds but also to words. Some of the Companions, may Allah be pleased with them, asked the Prophet, sallallaahu ‘alaihi wa sallam (may Allah exalt his mention), to make a tree for them that was known as “Thaat Anwaat”  so that they could hang their weapons on it in order to seek its blessings as the disbelievers used to do. The Prophet, sallallaahu ‘alaihi wa sallam, ( may Allah exalt his mention), responded:“By Allah, you have said to me the same as the Children of Israel said to Moosa; they said:{O Moosa make for us a god just as they have gods}.” [Ahmad and At-Tirmithi - Hasan Saheeh]  
The Prophet, sallallaahu ‘alaihi wa sallam, was asked about soothsayers, and he said:“They know nothing.” [Muslim] Even if soothsayers tell the truth once, they add to it a hundred lies.
The Prophet, sallallaahu ‘alaihi wa sallam, warned us many times about using graves as masjids (mosques). Allah The Almighty Says (what means): {And [He Revealed] that the masjids are for Allah, so do not invoke with Allah anyone.}[Qur’an 72:18] Therefore, it is the duty of all people to return in repentance to Allah The Almighty, submit themselves to Him, abandon any form of Shirk, Kufr (disbelief) or devoting any acts of worship to anything other than Allah and to believe in Him Alone. People must also know that Tawheed comes first, as one must give precedence to what is most important, whether in matters concerning seeking knowledge, work or Da‘wah.
The claims that the disbelievers, polytheists and philosophers have set the measures and foundations for good morals and that they have good manners is vain, as what is bred in the bone will come out in the flesh. Also, those disbelievers and polytheists will only benefit from their good deeds in this worldly life, but in the Hereafter they would embody the verse (what means):
{And We will regard what they have done of deeds and make them as dust dispersed.}[Qur’an 25:23]
{But those who disbelieved - their deeds are like a mirage in a lowland which a thirsty one thinks is water until, when he comes to it, he finds it is nothing but finds Allah before Him, and He will pay him in full his due; and Allah is swift in account.} [Qur’an 24:39]
Adhering to Legislation: All ways are blocked except that of the Prophet, sallallaahu ‘alaihi wa sallam, and it is not permissible, or indeed possible, to become firmly established with good morals first, then try to interpret Islamic texts in a way that would suit these morals. Allah the Almighty Says (what means): {O you who have believed, do not put [yourselves] before Allah and His Messenger, but fear Allah.} [Qur’an 49:1] In fact, we are required to derive our methodology, principles, and morals from the Qur’an and the Sunnah of the Prophet, sallallaahu ‘alaihi wa sallam, without permitting ourselves or others to neglect any of the Shari’ah texts. In this regard, we have to follow the example of the Prophet, sallallaahu ‘alaihi wa sallam, where we have many proofs. The Prophet, sallallaahu ‘alaihi wa sallam, saw a man walking during pilgrimage supported by two men, so he asked about him. The people informed him that he had vowed to go on foot to perform pilgrimage. He said: “Allah is not in need of this old man’s torturing himself.” Then he told the people: “Order him to ride.”[Al-Bukhari and Muslim]
 Also, when the Prophet, sallallaahu ‘alaihi wa sallam, saw Abu Israel, may Allah be pleased with him, standing in the sun and not speaking, he asked the people about him. They said, “He has vowed that on this day he will keep standing, remain in the sun and keep silent.” The Prophet, sallallaahu ‘alaihi wa sallam, said: “Let him end his fast, speak, come in the shade and sit down.” [Al-Bukhari] Sitting in the sun is a burden that does not bring the person closer to Allah the Almighty, and abstaining from speaking is how the previous nations used to fast, which is not a part of our Shari‘ah. The proof of this is what the Prophet, sallallaahu ‘alaihi wa sallam, said: “The one who believes in Allah and the Day of Judgment should say something good or remain silent.”
Further proof is that when the Prophet, sallallaahu ‘alaihi wa sallam, knew that ‘Abdullaah ibn ‘Amr, may Allah be pleased with him, was fasting during the daytime and performing voluntary prayers throughout the night, which made him neglect the rights of his wife, he said to him: “Fast like my brother, Daawood, [Prophet David, may Allah exalt his mention], who would fast every other day and never fled from his enemies.”[Muslim] It was also narrated that the Prophet, sallallaahu ‘alaihi wa sallam, said: “Your Lord has a right over you, and your wife has a right over you, so give each one his right.” [Al-Bukhari]
Thus, a person must be just, moderate and careful regarding the different benefits in life and should maintain a good balance between them, without excessiveness or negligence. One must also take the requirements of the body and soul into consideration, without aloofness or committing excess, and should have a comprehensive view of giving every person his due right.
Another example is when three men went to the houses of the Prophet, sallallaahu ‘alaihi wa sallam, asking about his acts of worship. When they were informed about it, it seemed as if they thought it was insufficient. Therefore, they said, “How can we compare ourselves to the Prophet sallallaahu ‘alaihi wa sallam, when his past and future sins have been forgiven.” Thereupon, one of them said, “I will offer voluntary prayers throughout the night and never sleep.” Another said, “I will fast throughout the year and will not break my fast.” The third said,“I will keep away from women and will never marry.” When the Prophet, sallallaahu ‘alaihi wa sallam, was told about them, he mounted the pulpit and gathered the people, then he said: “Why are some people saying such and such? I am the most knowledgeable and most fearful of Allah among you, yet I fast and break my fast, I offer voluntary night prayers and I sleep, and I marry women. Therefore, the one who does not follow my Sunnah, is not of my Ummah.” [Al-Bukhari and Muslim]
The path that leads to Allah the Almighty and the Gardens of Pleasure is the way of the Prophet, sallallaahu ‘alaihi wa sallam, that should not be exceeded. This way should be followed without innovations as the most perfect human is the Prophet, sallallaahu ‘alaihi wa sallamand his Sunnah is the praised way that was followed by his Companions, may Allah be pleased with them. The Sunnah is every thing that the Prophet, sallallaahu ‘alaihi wa sallam, did, said or approved of. It also includes any characteristic that was intended as a means of legislation for the Ummah. The one who turns away from the Sunnah of the Prophet, sallallaahu ‘alaihi wa sallam, should be told as the Prophet, sallallaahu ‘alaihi wa sallam, said: “The one who refrains from my Sunnah, is not of my Ummah.” The Prophet, sallallaahu ‘alaihi wa sallam, would say: “If someone innovates something that is not in harmony with the principles of our religion, that thing is rejected.” [Al-Bukhari and Muslim] It was narrated that the Prophet, sallallaahu ‘alaihi wa sallam, said: “Every innovation is deviation, and every deviation is in Hell.”
According to Ash-Shaatibi, may Allah have mercy upon him, an innovation is an invented way in the religion that is falsely attributed to the Shari‘ah, even though it is done with the intention of worshipping Allah The Almighty. Innovations are more preferable to Iblees (Satan) than sins, and the one who does them is among those to whom the evil of their deeds has been made attractive, so he considers them good. ‘Umar, may Allah be pleased with him, would say, “Every innovation is a deviation, even if people consider it to be good.” Ibn Mas‘ood, may Allah be pleased with him, would say, “Follow and do not innovate as you have what suffices you. Adhere to the way of the early generations [the Companions of the Prophet].”
The Companions, may Allah be pleased with them, followed this clear methodology and did not allow any one to ruin Tawheed or Legislation. ‘Umar ibn al-Khattab, may Allah be pleased with him, for instance, would kiss the Black Stone and say, “By Allah, I know that you are just a stone that can neither harm nor benefit, and I would have never kissed you if I had not seen the Prophet sallallaahu ‘alaihi wa sallam, kissing you.” ‘Ali, may Allah be pleased with him, dismissed all the people from the mosque who would tell imaginary and unreal stories under the pretext of reminding the people and softening their hearts. Also, when Ibn ‘Umar, may Allah be pleased with him, heard a man saying after sneezing, “Praise be to Allah and peace and blessing be upon the Prophet,” he told him, “This is not what the Prophet, sallallaahu ‘alaihi wa sallam, taught us. The Prophet said: ‘When anyone of you sneezes, he should praise Allah’ but he did not mention that we should ask for blessings upon him.”
When Ibn Mas‘ood, may Allah be pleased with him, entered the mosque of Al-Koofah, he saw groups of people sitting in circles and in the middle of each circle there was a pile of stones and a man standing by each group ordering them to exalt Allah The Almighty a hundred times, then to praise Him a hundred times, and then to glorify Him a hundred times, and the people responded. Ibn Mas‘ood, may Allah be pleased with him, said to them, “O people! By Allah you are either more guided than the Prophet sallallaahu ‘alaihi wa sallam, or you are approaching a deviation!” They said, “O Abu ‘Abdur-Rahmaan! We only meant to do good deeds.” He said, “There are many who want to do good deeds but never do [as they do not follow the Sunnah of the Prophet sallallaahu ‘alaihi wa sallam].” [Ad-Daarimi]
Any addition or deletion in acts of worship or behaviour that is done with the intention of drawing closer to Allah The Almighty, is a rejected innovation even if the intention was good as long as this act does not coincide with the Shari‘ah of Allah The Almighty.

Article source: http://www.islamweb.net/emainpage/