﴿ قُلْ فَلِلَّهِ ٱلْحُجَّةُ ٱلْبَٰلِغَةُ ۖ فَلَوْ شَآءَ لَهَدَىٰكُمْ أَجْمَعِينَ ﴾

“Say: "[Know,] then, that the final evidence [of all truth] rests with God alone; and had He so willed, He would have guided you all aright.”

Say if you have no definitive argument then ‘To God belongs the conclusive argument the perfect one for had He willed to guide you He could have guided all of you’.