Zakat is the third of five pillars in Islam. After giving the testimony of faith through the shahadah, we ought to prove our faithfulness by fulfilling our duty towards the Creator through salat and the five daily prayers, and then fulfill our duty towards the people who are the creation of Allah through zakat. Allah Almighty says:
وَأَقِيمُوا۟ ٱلصَّلَوٰةَ وَءَاتُوا۟ ٱلزَّكَوٰةَ وَٱرْكَعُوا۟ مَعَ ٱلرَّٰكِعِينَ
Establish prayer, pay alms-tax (zakat), and bow down with those who bow down. (al-Baqarah 2:43)
This connection between salat and zakat in a single ayah in the Qur’a\n was repeated twenty nine times in fifteen different suras. If salat was the main pillar of Islam, then zakat comes next in significance.
Denying zakat by rejecting it altogether or by neglecting and not fulfilling its obligation is a dangerous matter that could tantamount to the level of disbelief and could remove the person out of the fold of Islam. In a hadith, Abu Hurayrah may Allah be pleased with him narrated that the Messenger of Allah peace be upon him said:
" مَا مِنْ صَاحِبِ ذَهَبٍ وَلاَ فِضَّةٍ لاَ يُؤَدِّي مِنْهَا حَقَّهَا إِلاَّ إِذَا كَانَ يَوْمُ الْقِيَامَةِ صُفِّحَتْ لَهُ صَفَائِحَ مِنْ نَارٍ فَأُحْمِيَ عَلَيْهَا فِي نَارِ جَهَنَّمَ فَيُكْوَى بِهَا جَنْبُهُ وَجَبِينُهُ وَظَهْرُهُ كُلَّمَا بَرَدَتْ أُعِيدَتْ لَهُ فِي يَوْمٍ كَانَ مِقْدَارُهُ خَمْسِينَ أَلْفَ سَنَةٍ حَتَّى يُقْضَى بَيْنَ الْعِبَادِ فَيُرَى سَبِيلُهُ إِمَّا إِلَى الْجَنَّةِ وَإِمَّا إِلَى النَّارِ" .
“If any owner of gold or silver does not pay what is due on him, when the Day of Resurrection would come, plates of fire would be beaten out for him; these would then be heated in the fire of Hell and his sides, his forehead and his back would be cauterized with them. Whenever these cool down, (the process is) repeated during a day the extent of which would be fifty thousand years, until judgment is pronounced among servants, and he sees whether his path is to take him to Paradise or to Hell.” (reported by Muslim)