He who oppresses the poor shows contempt for their Maker, but whoever is kind to the needy honors God.
Proverbs 14:31
No one disagrees that Christians should care for, help and give to the poor. Most will even go along with the idea that helping the poor is part of "doing" the gospel. After all, there is nothing Jesus spoke more strongly about:
When the Son of Man comes in his glory, and all the angels with him, he will sit on his glorious throne. All the nations will be gathered before him, and he will separate the people one from another as a shepherd separates the sheep from the goats. He will put the sheep on his right and the goats on his left. Then the King will say to those on his right, 'Come, you who are blessed by my Father; take your inheritance, the kingdom prepared for you since the creation of the world. For I was hungry and you gave me something to eat, I was thirsty and you gave me something to drink, I was a stranger and you invited me in, I needed clothes and you clothed me, I was sick and you looked after me, I was in prison and you came to visit me.'
Then the righteous will answer him, 'Lord, when did we see you hungry and feed you, or thirsty and give you something to drink? When did we see you a stranger and invite you in, or needing clothes and clothe you? When did we see you sick or in prison and go to visit you?' The King will reply, 'Truly I tell you, whatever you did for one of the least of these brothers and sisters of mine, you did for me.' Then he will say to those on his left, 'Depart from me, you who are cursed, into the eternal fire prepared for the devil and his angels. For I was hungry and you gave me nothing to eat, I was thirsty and you gave me nothing to drink, I was a stranger and you did not invite me in, I needed clothes and you did not clothe me, I was sick and in prison and you did not look after me.'
They also will answer, 'Lord, when did we see you hungry or thirsty or a stranger or needing clothes or sick or in prison, and did not help you?' He will reply, 'Truly I tell you, whatever you did not do for one of the least of these, you did not do for me.' Then they will go away to eternal punishment, but the righteous to eternal life.
Matthew 25:31-46
Everyone agrees helping the poor is a good thing for a Christian to do. Most even believe it's part of the gospel. Unfortunately, some Christians think God only wants us to care for the poor with our personal charity; by sharing our private wealth. Somehow, they believe God doesn't care whether we promote public, social, and community policies that care for, help and give to the poor – or whether we promote the opposite policies.
Just as many conservative Christians seem to want to limit the gospel, so they also want to limit the biblical mandate for helping the poor. [I should clarify that I am mostly talking about white conservative Christian churches. If you visit a black conservative Christian church, you will see they "get" it.] These folks argue that the biblical mandate to care for the poor is an individual thing; not a community thing; not a government thing; not a political thing.
Conservative (usually evangelical, and of course, Republican) Christians argue that by advocating social and economic policies beneficial to the poor, we essentially are trying to force others (like rich people) to give to the poor. Conservatives argue that's not what the scriptures command; not what Christian values compel.
But, this simply is not true. First, as discussed in detail at the gospel and government, to say that Christians need only be concerned with individual charity, not systemic justice, is to ignore the reality of the world we live in. It is also to ignore the clear imperatives of scripture.
Do not deny justice to your poor people in their lawsuits.
Exodus 23:6
During the seventh year, let the land lie unplowed and unused. Then the poor among your people may get food from it, and the wild animals may eat what they leave. Do the same with your vineyard and your olive grove.
Exodus 23:11
When you reap the harvest of your land, do not reap to the very edges of your field or gather the gleanings of your harvest. Leave them for the poor and the alien. I am the LORD your God.
Leviticus 23:22
However, there should be no poor among you, for in the land the LORD your God is giving you to possess as your inheritance, he will richly bless you.
Deuteronomy 15:4
Defend the cause of the weak and fatherless; maintain the rights of the poor and oppressed. Rescue the weak and needy; deliver them from the hand of the wicked.
Psalm 82:3-4
For he stands at the right hand of the needy one, to save his life from those who condemn him.
Psalm 109:31
I know that the LORD secures justice for the poor and upholds the cause of the needy.
Psalm 140:12
I know that the LORD secures justice for the poor and upholds the cause of the needy.
Proverbs 13:23
A ruler who oppresses the poor is like a driving rain that leaves no crops.
Proverbs 28:3
The righteous care about justice for the poor, but the wicked have no such concern.
Proverbs 29:7
Speak up and judge fairly; defend the rights of the poor and needy.
Proverbs 31:9
Learn to do right! Seek justice, encourage the oppressed. Defend the cause of the fatherless, plead the case of the widow.
Isaiah 1:17
Woe to those who make unjust laws, to those who issue oppressive decrees, to deprive the poor of their rights and withhold justice from the oppressed of my people, making widows their prey and robbing the fatherless.
Isaiah 10:1-2
He defended the cause of the poor and needy, and so all went well. Is that not what it means to know me? declares the LORD.
Jeremiah 22:16
Now this was the sin of your sister Sodom: She and her daughters were arrogant, overfed and unconcerned; they did not help the poor and needy.
Ezekiel 16:49
So I will come near to you for judgment. I will be quick to testify against sorcerers, adulterers and perjurers, against those who defraud laborers of their wages, who oppress the widows and the fatherless, and deprive aliens of justice, but do not fear me,' says the LORD Almighty.
Malachi 3:5
When Jesus heard this, he said to him, You still lack one thing. Sell everything you have and give to the poor, and you will have treasure in heaven. Then come, follow me.
Luke 18:22
You can find many, many more bible verses about the poor at Worldvision and SNU.
I'll end with a couple quotes; both excellent. One from a Southern Baptist pastor; another from a liberal Christian.
If our lives do not reflect radical compassion for the poor, there is reason to question just how effective we will be in declaring the glory of Christ to the ends of the earth. More pointedly, if our lives do not reflect radical compassion for the poor, there is reason to wonder if Christ is really in us at all.
You and I both have a choice. We can stand with the starving or with the overfed. We can identify with poor Lazarus on his way to heaven or with the rich man on his way to hell.
David Platt, Radical: Taking Back Your Faith from the American Dream, pg. 111 and 140.
There was a rich man who was dressed in purple and fine linen and lived in luxury every day. At his gate was laid a beggar named Lazarus, covered with sores and longing to eat what fell from the rich man's table. Even the dogs came and licked his sores. The time came when the beggar died and the angels carried him to Abraham's side. The rich man also died and was buried. In Hades, where he was in torment, he looked up and saw Abraham far away, with Lazarus by his side. So he called to him, 'Father Abraham, have pity on me and send Lazarus to dip the tip of his finger in water and cool my tongue, because I am in agony in this fire.'
But Abraham replied, 'Son, remember that in your lifetime you received your good things, while Lazarus received bad things, but now he is comforted here and you are in agony. And besides all this, between us and you a great chasm has been set in place, so that those who want to go from here to you cannot, nor can anyone cross over from there to us.' He answered, 'Then I beg you, father, send Lazarus to my family, for I have five brothers. Let him warn them, so that they will not also come to this place of torment.' Abraham replied, 'They have Moses and the Prophets; let them listen to them.' No, father Abraham,' he said, 'but if someone from the dead goes to them, they will repent.' He said to him, 'If they do not listen to Moses and the Prophets, they will not be convinced even if someone rises from the dead.
Luke 16:19-31
As Mark Rosenfelder says:
There isn't the least suggestion that the rich man being punished in hell was responsible for Lazarus's condition... except in the most general sense: he was responsible as a fellow human being, as a man who was aware of the one suffering at his door and did nothing to help.
"Pleading the cause" of the poor, being their advocate and defender, is simply something a righteous person does. Are you someone who, when others are silent, advocates for the poor in your company, your church, your nation, your political party?
Here's more about the gospel and politics and the gospel and justice.