O mankind, the Messenger has come to you with the truth from your Lord, so believe; it is better for you. But if you disbelieve - then indeed, to Allāh belongs whatever is in the heavens and earth. And ever is Allāh Knowing and Wise.
(Verily, We have inspired you...) emphasized the Prophet's prophethood and refuted the idolators and People of the Scripture who denied him. Allah said,
لَّـكِنِ اللَّهُ يَشْهَدُ بِمَآ أَنزَلَ إِلَيْكَ
(But Allah bears witness to that which He has sent down unto you,) meaning, even if they deny, defy and disbelieve in you, O Muhammad, Allah testifies that you are His Messenger to whom He sent down His Book, the Glorious Qur'an that,
After answering the objections raised by the Jews and confirming the prophethood of Sayyidna Muhammad al-Mustafa, ﷺ the Qur'an carries the message of Allah to all human beings wherever they may be as they are its direct addressees this verse. The essence of the message is: Your salvation lies nowhere but in your belief in the prophethood of Muhammad ﷺ so, believe and prosper.
As for those who choose to disbelieve, they lose everything while Allah loses nothing. With His limitless domain and power, who can conceive of bringing any loss or harm to Him? This is something the disbelievers should worry about. Let them be certain that Allah knows everything about their believing and disbelieving and let not the delay or decrease in punishment in this world put them on the wrong foot for He is All-Wise too and does what His wisdom allows to prevail.
Tazkirul Quran
Maulana Wahiduddin Khan
Those who respond negatively to the call of God by ignoring and rejecting it show quite clearly that they have strayed far from true submission to God. They say such things as are refuted by the entire universe, and take up a position against a plan which is supported by the Lord of the universe. Obviously, there is no greater foolishness than this. Such perverse behaviour leads them into denying and rejecting God rather than acknowledging Him and submitting to Him. Day by day they are removed further away from the truth, until they ultimately fall into the pit of eternal damnation. The denial of the call of God is the denial of oneself. The call of God is made in such clear terms that no one should find any difficulty in understanding it. Moreover, those who deny the call of God are, as it were, showing their audacity in the face of God Himself. Impudence and presumptuousness are the greatest crimes in the eyes of God. If man were to keep the windows of his heart open, the divine call would appear to him an exact answer to his own quest. He would feel that the truth which had been veiled in human interpretations had been brought to him in its pure and original form by the arrangement of God Himself, and that it was an expression of God’s own wisdom and knowledge rather than its being a matter of the personal ambition of a human being.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.