The Islamic Stance on Democracy and Man-Made Law in 1, 2, 3!.

Firstly,

The one who does not rule by what Allah (azza wa ‘jal) revealed is a kaffir, and not ruling by what Allah (azza wa ‘jal) revealed has committed an action which takes one outside the fold of Islam.

“And whoever does not judge by what Allaah has revealed, then they are the disbelievers.” [Surah Al-Maa’idah: 44]

وَمَن لَّمْ يَحْكُم بِمَا أَنزَلَ اللّهُ فَأُوْلَـئِكَ هُمُ الْكَافِرُونَ

Secondly,

The legislation is ONLY for Allah (azza wa ‘jal).

The Hukm (judgment) is for none but Allâh. He has commanded that you worship none but Him, that is the (true) straight religion, but most men know not.” [Surat Yusuf :40]

إِنِ الْحُكْمُ إِلاَّ لِلّهِ أَمَرَ أَلاَّ تَعْبُدُواْ إِلاَّ إِيَّاهُ ذَلِكَ الدِّينُ الْقَيِّمُ وَلَـكِنَّ أَكْثَرَ النَّاسِ لاَ يَعْلَمُونَ

And the Prophet (Sallallahu ‘Alaayhe wa Salaam) that he said: “Verily, Allaah is the Hakam (ruler or judge) and to Him is the Hukm (judgment).”

Thirdly,

Obeying legislation is Ibaadah (Worship)

“They (Jews and Christians) took their rabbis and their monks to be their lords besides Allah” [Surat al-Tawbah: 31]

اتَّخَذُواْ أَحْبَارَهُمْ وَرُهْبَانَهُمْ أَرْبَابًا مِّن دُونِ اللّهِ

‘Adiyy bin Haatim (Radiyallahu ‘Anhu), who was a Christian but came to Islam, he heard the Prophet (Sallallahu ‘Alaayhe wa Salaam) recite this ayah, so ‘Adiyy (Radiyallahu ‘Anhu) said: ‘We did not worship them besides Allah’. The Prophet (Sallallahu ‘Alaayhe wa Salaam) replied: ‘Did they not make forbidden what Allah had made permissible, and made permissible what Allah had made forbidden?’ ‘Adiyy (Radiyallahu ‘Anhu) replied: ‘Of course’. So He (Sallallahu ‘Alaayhe wa Salaam) said: ‘So that was your worshipping of them’.

[Found in Imam Ahmad’s Musnad and the Jaami’ of at-Tirmithi, and he declared it hasan]