Say: whoever is in error, the Most Gracious will extend ﴿circumstances﴾ for him, until, when they see that which they were promised, either the torment or the Hour, they will come to know who is worst in position, and who is weaker in forces.
Allah, the Exalted, says,
(Say) This means, "O Muhammad, say to these people who are associating partners with their Lord, while claiming to follow the truth, that they are really following falsehood.''
(whoever is in error) This means, `be they from us or from you.' (the Most Gracious will extend ﴿circumstances﴾ for him.) This means that the Most Beneficent will give him respite in that which he is in, until he meets his Lord and his appointed time will have arrived.
(until, when they see that which they were promised, either the torment) that will strike him, (or the Hour) that will come suddenly, (they will come to know) at that time, (who is worst in position, and who is weaker in forces.) This is in refutation of thier argument about their nice dwellings and splendid places of gathering. This is a challenge against the idolators who claim that they were following guidance in what they were doing. This is similar to the challenge that Allah mentions about the Jews when He says,
(O you Jews! If you pretend that you are friends of Allah, to the exclusion of (all) other people, then long for death if you are truthful.) ﴿ [62:6] ﴾ Meaning, `Supplicate for death to come to those who are following falsehood among us if you truly claim to be upon the truth. If you are true, then this supplication will not harm you.' But they refused to do so. An extensive discussion of this has already preceded in Surat Al-Baqarah, and to Allah is the praise. Likewise, Allah mentioned the challenge that was given to the Christians in Surah Al `Imran, when they were persistent in their disbelief and continued in their transgression. They refused to give up their exaggerating claim that `Isa was the son of Allah. Therefore, Allah mentioned His arguments and proofs against the worship of `Isa, and that he was merely a creature like Adam. After this, Allah said,
(Then whoever disputes with you about him after (all this) knowledge that has come to you, say: "Come, let us call our sons and your sons, our women and your women, ourselves and yourselves - then we pray and invoke (sincerely) the curse of Allah upon those who lie.'') ﴿ [3:61] However, they (the Christians) also retreated from this challenge.
Those who are against Allah (SWT) and promote false hood will be eventually brought to punishment in the hereafter even though they may be given respite in this life. Allah (SWT) is All Knowing and Just. Each action will be rewarded accordingly. Those who believe that they would not be called to account for their actions are living in "falsehood" themselves.