The Ṣalāh is the most crucial affair in a Muslim’s life. To preserve one’s religion, one has to observe it consistently; otherwise, one would be negligent of the Ṣalāh, let alone other acts of worship. It is the pillar of Islām, as it is soundly reported from the Prophet (May Allah elevate his rank & grant him peace). At the same time, the remaining deeds serve as the axis of support. Similarly, a tent without a pillar is useless. The Ṣalāh is the criterion for accepting all other deeds; if it is rejected [by Allāh], all other deeds will be rejected. It is the first obligation ever in Islām and the last act of worship to wither. So, if one is negligent to the first and the last thing in Islām, then one will lose everything in-between.
Inadequate observance of the Ṣalāh that lacks adherence to its prescribed form in the manner performed by the Messenger of Allāh (May Allah elevate his rank & grant him peace) will derail one’s religion. It will invalidate all deeds, cause misconduct in one’s religious and worldly affairs.