The truest word uttered by a poet is this verse of Labid: "Behold! apart from Allah everything is vain," and Umayya b. Abu Salt was almost a Muslim. (Using translation from Muslim 2256b)
قَالَ رَسُولُ اللهِ ﷺ أَصْدَقُ كَلِمَةٍ قَالَهَا شَاعِرٌ كَلِمَةُ لَبِيدٍ[البحر الطويل]أَلَا كُلُّ شَيْءٍ مَا خَلَا اللهَ بَاطِلُوَكَادَ أُمَيَّةُ بْنُ أَبِي الصَّلْتِ أَنْ يُسْلِمَ