وَلَيَعْلَمَنَّ اللَّهُ الَّذِينَ آمَنُوا وَلَيَعْلَمَنَّ الْمُنَافِقِينَ ﴿۱۱﴾ وَقَالَ الَّذِينَ كَفَرُوا لِلَّذِينَ آمَنُوا اتَّبِعُوا سَبِيلَنَا وَلْنَحْمِلْ خَطَايَاكُمْ وَمَا هُمْ بِحَامِلِينَ مِنْ خَطَايَاهُمْ مِنْ شَيْءٍ إِنَّهُمْ لَكَاذِبُونَ ﴿۱۲﴾ وَلَيَحْمِلُنَّ أَثْقَالَهُمْ وَأَثْقَالًا مَعَ أَثْقَالِهِمْ وَلَيُسْأَلُنَّ يَوْمَ الْقِيَامَةِ عَمَّا كَانُوا يَفْتَرُونَ ﴿۱۳﴾

﴾11﴿ Wa la ya'lamannal laahul lazeena aamanoo wa la ya'lamannal munaafiqeen
﴾12﴿ Wa qaalal lazeena kafaroo lillazeena aamanut tabi'oo sabeelanaa walnahmil khataayaakum wa maa hum bihaamileena min khataa yaahum min shai'in innahum lakaaziboon
﴾13﴿ Wa la yahmilunna asqaa lahum wa asqaalam ma'a asqaalihim wa la yus'alunna Yawmal Qiyaamati 'ammaa kaanoo yaftaroon

﴾11﴿ And indeed, Allah will make clear those who have believed and indeed, He will expose the hypocrites
﴾12﴿ And those who disbelieve say to those who believe, "Follow our path, and we will bear your sins." But they will not bear any of their sins; indeed, they are liars
﴾13﴿ And indeed, they will carry their own burdens and burdens along with their burdens of leading others astray. And indeed, they will be questioned on the Day of Judgment about what they used to fabricate

[11] This is the result of the earlier trial — meaning, whoever remains firm upon the truth during the harm and opposition of people, then he is a true believer.
In verse (3), the result was about general trials through which truthfulness and falsehood become known.
And in this verse, the trial is related to saying “We believe” (آمَنَّا), which becomes a means of recognizing sincerity and distinguishing it from hypocrisy.
[12] This is the fourth trial — meaning, the disbelievers and polytheists call others to shirk and encourage the concealment of the truth. They say that the burden of the sin (from your actions) will be upon us.
Zamakhshari and Khateeb Shirbini have stated that such situations have also begun to appear among Muslims — where they call others to conceal the truth and commit sins, saying that the burden and punishment for it will be on them.
"(And let us bear your sins - وَلْنَحْمِلْ خَطَايَاكُمْ)" — this is in the form of a condition, meaning: if you follow our way, then we will take responsibility for your sins.
This claim is refuted in two ways:
1. "(And they will not bear them - وَمَا هُمْ بِحَامِلِينَ)" — similar to the verse: No bearer of burdens will bear the burden of another (Surah Fatir 35:18 and Surah Najm 53:38).
2. "Indeed, they are surely liars - إِنَّهُمْ لَكَاذِبُونَ".
[13] This is a third way of refuting their claim, and it serves as a warning of punishment in the Hereafter.
"(And burdens - وَأَثْقَالًا)" refers to those sins that will be added to them because of leading others astray — just like in Surah An-Nahl (16:25).