He does not want you to believe just because others do. So use your thinking ability to gain accurate knowledge.
وَهٰذِهِ ٱلْقُوَّةُ ٱلْعَقْلِيَّةُ سَتُسَاعِدُكَ عَلَى نَيْلِ ٱلْمَعْرِفَةِ ٱلدَّقِيقَةِ .‏