Why do you feel the need to lie?

If a person really believes on something, and if that belief is being threatened, he/she will defend it vigorously fair or foul...

This has occurred in the scientific field for similar reasons to those mentioned above and also when someone has felt devoted to a particular view or when they might stand to benefit in some way. Some examples would be the Piltdown Man hoax, the Peppered Moths and the fraudulent drawings made by Ernest Haeckel, all used to promote the theory of evolution.

Lies also more readily occur when people have no moral compass to guide them, such as when they deliberately reject Biblical teaching and replace it with their own subjective standard.

The Bible says the origin of deceit is in the heart, ' The heart is deceitful above all things, and desperately wicked: who can know it?' Jeremiah 17 v9. This is all part of the fallen sinful nature which Christian believers are to get rid of. 'Lie not one to another, seeing that you have put off the old man with his deeds.' Colossians 3 v 9