“There is nothing standing between a person and Shirk (polytheism) except leaving the prayer, so if he leaves it he has committed Shirk.”
عَنِ النَّبِيِّ ﷺ قَالَ لَيْسَ بَيْنَ الْعَبْدِ وَالشِّرْكِ إِلاَّ تَرْكُ الصَّلاَةِ فَإِذَا تَرَكَهَا فَقَدْ أَشْرَكَ