the sentence means that..if we share our views with others..we will get different opinions from others and our knowledge about it will increase..

The sentence is philosophical, religious or spiritual. It is basically about helping others who are in need. It assumes that the more 'things' we give to others, the more 'things' we will have because of our good deeds. 'Things' could mean anything physical like 'money', 'clothes' etc or something non-physical like 'Love', 'Happiness'. There is a great description I found at this link: http://www.helium.com/items/1813221-the-more-we-share-the-more-we-have It can be used as a idiom when you want to tell someone that it is a good thing to share their things with others. For e.g. 'italki.com is a living example that the more we share, the more we have. Language students from all over the world are greatly benefiting by helping others and by being helped in return' :-)

it means that if you give someting, then you get something...but if you give more, you will get more things in your life

You can understand it by the term 'It is better to give than receive"

what you give if what you get