Micah 6.8 says:

O people, the LORD has told you what is good, and this is what he requires of you: to do what is right, to love mercy, and to walk humbly with your God.

We can hardly overstate the emphasis the Bible places on justice as a matter very close to the heart of God. Yahweh repeatedly called for Israel to show justice to the aliens, widows, orphans, and aliens in the land.

Isa. 1 stands out as one of the strongest prophetic declarations of this sort:

“What makes you think I want all your sacrifices?”
    says the Lord.
“I am sick of your burnt offerings of rams
    and the fat of fattened cattle.
I get no pleasure from the blood
    of bulls and lambs and goats.
When you come to worship me,
    who asked you to parade through my courts with all your ceremony?
Stop bringing me your meaningless gifts;
    the incense of your offerings disgusts me!
As for your celebrations of the new moon and the Sabbath
    and your special days for fasting—
they are all sinful and false.
    I want no more of your pious meetings.
I hate your new moon celebrations and your annual festivals.
    They are a burden to me. I cannot stand them!
When you lift up your hands in prayer, I will not look.
    Though you offer many prayers, I will not listen,
    for your hands are covered with the blood of innocent victims.
Wash yourselves and be clean!
    Get your sins out of my sight.
    Give up your evil ways.
Learn to do good.
    Seek justice.
Help the oppressed.
    Defend the cause of orphans.
    Fight for the rights of widows.

Jesus echoed this in Matt. 25.31-46 where he equated care for the hungry, thirsty, naked, sick, and imprisoned with care for himself.

“But when the Son of Man comes in his glory, and all the angels with him, then he will sit upon his glorious throne. All the nations will be gathered in his presence, and he will separate the people as a shepherd separates the sheep from the goats. He will place the sheep at his right hand and the goats at his left.

“Then the King will say to those on his right, ‘Come, you who are blessed by my Father, inherit the Kingdom prepared for you from the creation of the world. For I was hungry, and you fed me. I was thirsty, and you gave me a drink. I was a stranger, and you invited me into your home. I was naked, and you gave me clothing. I was sick, and you cared for me. I was in prison, and you visited me.’

“Then these righteous ones will reply, ‘Lord, when did we ever see you hungry and feed you? Or thirsty and give you something to drink? Or a stranger and show you hospitality? Or naked and give you clothing? When did we ever see you sick or in prison and visit you?’

“And the King will say, ‘I tell you the truth, when you did it to one of the least of these my brothers and sisters, you were doing it to me!’

“Then the King will turn to those on the left and say, ‘Away with you, you cursed ones, into the eternal fire prepared for the devil and his demons. For I was hungry, and you didn’t feed me. I was thirsty, and you didn’t give me a drink. I was a stranger, and you didn’t invite me into your home. I was naked, and you didn’t give me clothing. I was sick and in prison, and you didn’t visit me.’

“Then they will reply, ‘Lord, when did we ever see you hungry or thirsty or a stranger or naked or sick or in prison, and not help you?’

“And he will answer, ‘I tell you the truth, when you refused to help the least of these my brothers and sisters, you were refusing to help me.’

“And they will go away into eternal punishment, but the righteous will go into eternal life.”

It is clear that our God identifies with those in need of justice, with those society is most prone to treat unfairly. As followers of Jesus, this needs to be close to our hearts just as it is close to God’s heart.