Imam Ridha says:
“Do not disregard the Words of Allah (the holy Qur'an), and do not seek guidance from other than Him, for then (surely) you will go astray.”
Every producer in the world that makes something will have a brochure or manual on their product which details how to use the item, and the purchaser, in order to maximize their benefit of their new acquisition, will read the manual in order to understand how to best benefit from the product.
Who authors these manuals? Is it any one other than the designers and producers of the product? No.
We also have a designer and creator who alongside with our creation has sent down for us a manual named the Holy Qur’an, and no one has the right to implement a law which opposes the Divine Laws within the Qur’an. This is because only the Creator knows what He created in totality and is aware of every corner of His creation, knows what is best for His creation and what is detrimental.
"Can He who has created not know (His creation)? While he is the All-attentive, the All-aware."1
Imam Ali (AS) says:
'In the Qur'an there is the cure for the greatest sickness, which is disbelief, hypocrisy, error, and deviation.' 2
Whoever makes new man-made laws to replace the laws of the Creator is like the one who leaves the manual from the primary source behind to follow the instructions of others. As Imam Ridha says:
“Do not disregard the Words of Allah (the holy Qur'an), and do not seek guidance from other than Him, for then (surely) you will go astray.” 3
The holy Qur'an is a universal and eternal book which contains all the needs of human beings, it is not specified for any race or tribe, rather it is meant for all human beings in every era and every place, it does not get old with the passage of time . the holy prophet (pbuh)said,
"Allah, Blessed and most High, did not make the Quran for a certain time and not another, or for certain people and not others. It is new in every time and fresh for all people until the Day of Judgment." 4
----------------------------------------------------------------------------------
1. Al Mulk 67:14
أَلَا يَعْلَمُ مَنْ خَلَقَ وَهُوَ ٱللَّطِيفُ ٱلْخَبِيرُ
2. إنّ فيهِ شِفاءً مِن أكبَرِ الداءِ ، وهُو الكُفرُ والنِّفاقُ ، والغَيُّ والضَّلالُ
Nahj al-Balagha, Sermon176
3. ‘Uyunul Akhbar ar-Ridha, Volume 2, Page 57
كَلامُ اللّهِ لا تَتَجاوَزُوهُ وَ لا تَطْـلُـبُوا الْهُدى فِي غَيْرِهِ فَتَضِلُّوا
4.Bihar al-Anwar, v. ۹۲, p. ۱۵, no. ۸
لأنَّ اللَّهَ تباركَ وتعالى لم يَجعَلْهُ لِزمانٍ دونَ زَمانٍ ، ولا لِناسٍ دونَ ناسٍ ، فهُو في كلِّ زَمانٍ جَديدٌ ، وعِند كُلِّ قَومٍ غَضٌّ إلى يَومِ القِيامَةِ