Why did Imam Khomeini maintain that Islamic system is obliged to undertake implementation of law?

Why did Imam Khomeini see necessity for establishing government?

President Rouhani says US sanctions strengthen unity between Iranian nation, government:

Iran’s President Hassan Rouhani says Washington’s “maximum pressure” campaign has failed to achieve its objectives and only strengthened unity between the government and people.

Politics and Religion in contemporary Iran

The most important characteristics of politico-jurisprudental religiosity are: total Islamic discourse in which political and religious affairs are inseparable. Seeking a religious government and society and he establishment and implementation of Sharia laws in such a society; and Opposition to secularism and nationalism.

Imam Khomeini defined genuine political facet

Imam Khomeini defined Ghadir as most magnificent feast

Imam Khomeini through his theological works and historical messages maintained that Ghadir is the completion of the religion, the perfection of God’s greatest bounty, the most magnificent feast of Allah; it is the feast for the righteous people, followers and supporters of the holy Prophet of Islam.

Imam Khomeini established Islamic Republic, promoted democracy

Imam Khomeini stressed need for strong family foundations

Imam Khomeini, the late founder of the Islamic Republic, raised statues of women and encouraged their participation in all social, cultural and political arenas following the victory of the Islamic revolution under his wise leadership in 1979. He observed rights of others in all thick and thin times and all circumstances and stressed the need to strengthen the foundations of family.