This promise is the most noble one to do as when we tend to help someone without expecting something in return we are rendered blessings multifold by God.
The term Helping others seem big but it need not be in reality. It started with the intention to see others smile or relive from pain. It may be a brief relief but that time frame may give the Person a hope to live and new strength to pursue further.
This help may be monetary, physical support or emotional support or even a small hug. When you render this support to others in need, you are perceived in a position equivalent to God to the people at the receiving end. God has given this privileged position only to those who are eager to share others pain and try to reduce it.
Also as a human being blessed with six senses and being in God’s unlimited Grace it’s our duty too to help others.
A small excerpt from the Proverbs 3:27
Do not withhold good from those to whom it is due, When it is in your power to do it.
God who rules us gave up his comforts and came to this world only to help us reliever from sin. Is it not time to repay that favour by helping others?