An episode of Moksha Dharma Parva of the Mahabharata has the story of a conversation between a king by name Yadhu, and an ascetic who explains how he learnt lessons from nature.
After mentioning many teachers he speaks about air. Air circulates freely everywhere but nothing sticks to it permanently. An odour may waft through the air but the air is not one with the odour. As the air moves on, the odour is left behind. A human being must behave similarly in the company of bad people or under the influence of bad thoughts. He must move on without such people or thoughts affecting him.
The ascetic proceeds to tell the king that water has superlative contrasting qualities. Firstly, the cleansing nature of water; as adapted to a human is particularly that of the mind and a person should try to dissuade another from doing wrong or speaking badly - either as an atheist or simply bad-mouthing others for some pleasure.
The person advising the other should himself be clean in mind and deed, as muddy water cannot cleanse anything. Have we ever wondered that loose mud or clay can be fashioned into a pot only by adding water which makes the particles stick together? Back in the kitchen loose roti flour becomes a homogeneous dough by the addition of water. Thus water has this binding nature.
Human beings are advised to adopt the quality of water which cleans as well as brings together substances.
The third quality attributed to water is friendship, with the binding going beyond substances to building bonds of friendship, and a person should try his best to bring together people for a noble cause. Although an individual can do virtuous deeds alone the synergy that emerges from a group effort is stupendous.
It can be compared to a situation when water is poured from a tumbler and a big pitcher onto a surface. The quality of water is the same but the quantity makes a differential impact on the surface. By natural extension friendship goes to include affection, starting from a parent towards the child which is natural and purely God given, and which nurtures an infant into a healthy individual. One should be grateful to the Almighty for this.