Word by Word Analysis

وَلَئِنْ أَتَيْتَ ٱلَّذِينَ أُوتُوا۟ ٱلْكِتَـٰبَ بِكُلِّ ءَايَةٍ مَّا تَبِعُوا۟ قِبْلَتَكَ ۚ وَمَآ أَنتَ بِتَابِعٍ قِبْلَتَهُمْ ۚ وَمَا بَعْضُهُم بِتَابِعٍ قِبْلَةَ بَعْضٍ ۚ وَلَئِنِ ٱتَّبَعْتَ أَهْوَآءَهُم مِّنۢ بَعْدِ مَا جَآءَكَ مِنَ ٱلْعِلْمِ ۙ إِنَّكَ إِذًا لَّمِنَ ٱلظَّـٰلِمِينَ 145

And if you brought to those who were given the Scripture every sign, they would not follow your qiblah. Nor will you be a follower of their qiblah. Nor would they be followers of one another's qiblah. So if you were to follow their desires after what has come to you of knowledge, indeed, you would then be among the wrongdoers.