Jesus commanded us to give freely, to lend expecting nothing in return. This applies to all of our life, not just our money.
How often do we give expecting certain results? We give kind words, we help, we give time, money, labor; we do all this expecting some kind of result. We "minister" in various ways--of course it is not really ministry, for if it were, we would merely be doing our duty, fulfilling our calling with no expectation, like a slave, which is what "minister" means. But we expect results. Often we don't even know how to think about giving without first thinking about what we want our giving to accomplish.
The results that we expect vary. We might expect that our good example will be followed by others; or that the Grace of God will touch someone's heart because of what we have done; or that someone will change their ways (even just slightly) because of some word or act or grace or gift that we have given. We expect good things. Yet even to expect good things is not really to give freely.
When Jesus told the rich ruler to sell all he had and give the money to the poor and follow Him, Jesus wasn't telling him the way to fix the problem of poverty. Jesus was telling him how he could be saved. Giving saves us. We give because God gives, and in giving we begin to imitate God. What others do or don't do with the gift is a separate matter completely.
For me, it is easier to apply this principle to money. It is easier, but not easy. When it comes to other things that I give away--time, labour, words, care, tears--when it comes to these things, it is much harder not to expect some good result--or some result that I would recognize as good. It is hard to give love freely. It is hard to give care freely. It is hard to freely weep with those who weep.