The Groups
أَلَيْسَ ٱللَّهُ بِكَافٍ عَبْدَهُۥ ۖ وَيُخَوِّفُونَكَ بِٱلَّذِينَ مِن دُونِهِۦ ۚ وَمَن يُضْلِلِ ٱللَّهُ فَمَا لَهُۥ مِنْ هَادٍ
Is not Allah sufficient for His Servant [Prophet Muhammad]? And [yet], they threaten you with those [they worship] other than Him. And whoever Allah leaves astray - for him there is no guide.
Nearby ayahs help place verse 39:36 in sequence and meaning.
لَهُم مَّا يَشَآءُونَ عِندَ رَبِّهِمْ ۚ ذَٰلِكَ جَزَآءُ ٱلْمُحْسِنِينَ
They will have whatever they desire with their Lord. That is the reward of the doers of good -
لِيُكَفِّرَ ٱللَّهُ عَنْهُمْ أَسْوَأَ ٱلَّذِى عَمِلُوا۟ وَيَجْزِيَهُمْ أَجْرَهُم بِأَحْسَنِ ٱلَّذِى كَانُوا۟ يَعْمَلُونَ
That Allah may remove from them the worst of what they did and reward them their due for the best of what they used to do.
وَمَن يَهْدِ ٱللَّهُ فَمَا لَهُۥ مِن مُّضِلٍّ ۗ أَلَيْسَ ٱللَّهُ بِعَزِيزٍ ذِى ٱنتِقَامٍ
And whoever Allah guides - for him there is no misleader. Is not Allah Exalted in Might and Owner of Retribution?
وَلَئِن سَأَلْتَهُم مَّنْ خَلَقَ ٱلسَّمَـٰوَٰتِ وَٱلْأَرْضَ لَيَقُولُنَّ ٱللَّهُ ۚ قُلْ أَفَرَءَيْتُم مَّا تَدْعُونَ مِن دُونِ ٱللَّهِ إِنْ أَرَادَنِىَ ٱللَّهُ بِضُرٍّ هَلْ هُنَّ كَـٰشِفَـٰتُ ضُرِّهِۦٓ أَوْ أَرَادَنِى بِرَحْمَةٍ هَلْ هُنَّ مُمْسِكَـٰتُ رَحْمَتِهِۦ ۚ قُلْ حَسْبِىَ ٱللَّهُ ۖ عَلَيْهِ يَتَوَكَّلُ ٱلْمُتَوَكِّلُونَ
And if you asked them, "Who created the heavens and the earth?" they would surely say, "Allah." Say, "Then have you considered what you invoke besides Allah? If Allah intended me harm, are they removers of His harm; or if He intended me mercy, are they withholders of His mercy?" Say, "Sufficient for me is Allah; upon Him [alone] rely the [wise] reliers."