Why was only justice selected from among all attributes of God to became one of the five pillars of religion?

In response to this important question, several points should be noted:
1. Among God’s Qualities, justice is so important that many other Qualities return to it because justice in the general, extensive sense means ‘putting everything in its place’.

Here, then, Hakim, Razzaq, Rahman and Rahim, and similar Qualities, are all dependent upon it.
2. Resurrection — just as we have mentioned — is related to Divine Justice as well as the mission of the Prophet and the responsibility of the Imams.
3. At the beginning of Islam, a difference of Opinion arose over the issue of the justice of the Creator:

A group of the Sunni Muslims, who were called the Ash’arites, completely denied God’s justice. They said that justice and oppression make no sense in relation to God. He is the Ruler of the entire created universe. It belongs to Him and whatever He does is just.
They did not even believe in the intellect’s good and evil. They said, “Our intellect alone cannot distinguish between good and bad, even the goodness of doing good or the evil of oppression…” and many such similar errors.
Another group of the Sunnis, who were called the Mu’tazilites, and all of the Shi’ites, believe in the principle of justice in relation to the Creator and they believe that God never commits oppression.

In order to separate out those two groups from one another, they called the second group, the Adliyah, in which justice (adl), as a principle, was the sign of the school and the first group were called ‘qhayr adliyah’ (other than justice). Shi’ites were among the ‘Adliyah.
The Shi’ites, in order to distinguish their school from that of the other Adliyah, placed imamate as one of the principles as well. Thus, wherever there is a discussion of ‘justice’ and ‘imamate’, this is in reference to the Shi’ite Imami school.

4. As the fundamentals of religion are continuous rays of the principles of religion and as the ray of justice of the Creator is extremely effective in human society, and the most important base for human society is formed by ‘social justice’, the selection or choice of the principle of justice as one of the principles of religion is a means to establish justice in human society and to struggle against any kind of oppression.

Just as the unity of Essence, Qualities of the Creator, the unity of worship of Him, the light and unity of His Oneness, a solidification of human society and the unity of Qualities are strengthened, the leadership of the prophets and imams is also inspired by the issue of ‘real leadership’ in human society. Thus, this principle of justice of the Creator, who rules over the entire world, is the sign of the necessity for justice in all areas of human society.

The great created universe is based upon Divine Justice. Human society will also not remain without it.1

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1) Fifty Lessons on Principles of Belief for Youths, written by Ayatullah Naser Makarem Shirazi,