It is known, from the proofs of the Qur'an and Sunnah that seeking nearness by slaughtering to other than Allaah, such as pious people, Jinn, idols, or any other creatures, is Shirk and practices of pre-Islamic era and the pagans. Allaah, the Exalted says: Say, My Salah, and offering, and my life, and my death are all for Allaah, the Lord of the worlds. He has no partner. And so am i commanded, and I am the first of the Muslims.  Allaah, Glorious is He, clarifies in this Verse that sacrificing to other than Allaah is Shirk, just as performing the prayer to other than Him. Allaah, the Exalted, says: We have given you al-Kawthar. So pray to your Lord and offer sacrifice.  In this Surah Allaah, Glorious is He, instructed His Prophet to pray to His Lord, and sacrifice to Him, contrary to the people of Shirk who pray and slaughter to other than Allaah. Allaah, the Exalted says: And your Lord has decreed that you should worship none other than Allaah.  He also says: And they commanded only to worship Allaah, being sincere to Him  There are many Verses that convey this meaning. Since sacrifice is a act of worship, then it must be dedicated sincerely to Allaah. Imam Muslim narrated in his Sahih that the Commander of the Believers, Ali said that the Messenger of Allaah (sallallaahu alaihi wa sallam) said: Allaah curses him who sacrifices to other than Allaah  As for those who say: I adjure Allaah by the right of His beloved believers, or by the honour of His beloved believers, or by the right of the Prophet, or by his honour. Such adjuration does not constitute Shirk, but it is an innovation, according to the assembly of people of knowledge and means of Shirk, because of the supplication is an act of worship, and the way it should be made is not subject to opinion. There is no proof related to the Prophet (sallallaahu alaihi wa sallam) denoting legality, or permissibility or duration by the right or honour of any human. Hence, it is not permissible for the Muslims to innovate a type of Tawassul (a duration) which Allaah, the Exalted, does not legitimise. Allaah, the Exalted, says: Or do they have partners who legalise for them acts of worship which Allaah does not permit.  And the Prophet (sallallaahu alaihi wa sallam) said: He who imitates in this matter of ours that is not from it, shall have it rejected  His statement shall have it rejected
means that it shall not be accepted by Allaah from the one who introduces it. It is incumbent upon the Muslims to restrict themselves only to what Allaah has legitimised, and to beware of what people innovate. As for the legitimate Tawassul, it is adjuring Allaah Names and Attributes. It can be effective by upholding the beliefs in His Oneness, doing good deeds, charitable donations and by believing in Allaah and His Messengers. It is Allaah who grants success.
 Awliya, pl. Of Waliy, a favourite of Allaah.  Al-Anam 6:162,163  Al-Kawthar 108:1,2  Al-Israa 17:23  Al-Bayyinah 98:5  Muslim no. 1978  Ash-Shura 42:21  Al-Bukhari no. 2697 and Muslim no. 1718