Receive God’s blessing
God loves those who love His creation. If you are kind to the people and go out of your way to help them out by giving them something that you own, then God would surely shower you with his blessing.
Helps a person in moving on
If there are things that remind you of an ex or a dead beloved, then it is best to part with those things. Since they are invaluable to you, you cannot just throw them away. The best thing to do in such a situation is to give them to someone who can use them.
Make space for new stuff
In order to create more space for the new stuff that you buy, you will find yourself compelled to do away with the old stuff that you own such as clothes, books, shoes, etc. The best thing to do about the stuff that you need to get rid of is to donate them to the under-privileged.
Make the under-privileged happy
One really does not need a reason to make others happy. The mere sight of joy on the face of an under-privileged person when you donate a possession to him is a huge reward in its own.
There are certain things that a person must do out of moral obligation. Nobody can force you to donate stuff. It is entirely a personal choice. However, your conscience would feel at ease if you donate stuff.
Take care of others
You should take care of others instead of turning away from those who are not blessed as you. Do not let caste, creed, or anything of that sort come in the way of your love for humanity.