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.