In the Name of Allah, the Most Gracious, the Most Merciful.
The Command to defy the Disbelievers and Hypocrites by followingthe Revelation of Allah and putting One's Trust in Him
Here Allah points out something lower by referring to something higher. When He commands His servant and Messenger to do this, He is also commanding those who are lower than him, and the command is addressed to them more so. Talq bin Habib said: "Taqwa means obeying Allah in the light of the guidance of Allah and in hope of earning the reward of Allah, and refraining from disobeying Allah in the light of the guidance of Allah and fearing the punishment of Allah."
Once again, the last statement: وَتَوَكَّلْ عَلَى اللَّـهِ ۚ وَكَفَىٰ بِاللَّـهِ وَكِيلًا (And place your trust in Allah and Allah is enough as a guardian- 3) is also a complement of the same order. Here it is being said: As for your approach, just pay no heed to what they say and, in order to succeed in your objective, you should trust no one but Allah for He, in Himself and by Himself, is the ultimate doer, maker and fixer of all matters and things. With Him there, you do not need to acquiesce in the opinion of anyone.
Ruling
The cited verse proves that, in religious matters, even consulting with disbelievers is not permissible. In other matters relating to technical or functional experience, there is no harm in doing so. And Allah knows best.
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 3–4
The Prophet Muhammad was the call-giver of the purest Truth. In this world, one who rises as such has to face the most discouraging circumstances. He remains a stranger in his surroundings. The prevalent creed, based as it is on worldly considerations, does not accord with the Hereafter-oriented religion of the missionary. Time-serving tendencies clash with his fearless policy of following the Truth. Religion has been made subservient to communal beliefs, while the missionary demands that religion should be based purely on worship of God. Under these circumstances, if a preacher succumbs to the pressure of his surroundings and makes compromises, he may attract many supporters. If he is firm in the way of Truth, he will find no support except that of the one and only God. But, the call-giver must not adopt the first alternative under any circumstances. He has to trust in God, stick to the unadulterated Truth and hope that as God is All-knowing and Wise, He will definitely help His subject.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.