Mumford & Sons' lyrics are heavily laden with literary content, needless to say that this song does too. In the one sentence: this song, it could be interpreted, refers to a call for the realization of man's humanity. This is what I interpret to mean 'soul'. 

Our 'woozy eyes' and 'fickle heart' refer to the clouded perception of our awareness of this 'sleeping' humanity and we find it difficult to find our true sense of expression.

This can be attributable to our contemporary society and the complexities of our interaction between others and the world. There are divisions which have been established historically which perpetuate the separation of ourselves from our true-selves (soul) and the love that exists between one another. (eg. Racism, sexism, nationalism, rich and poor)

Our society is wrought with myths and people telling us what we should know and what and how we should think and act. So much so that we 'struggle to find any truth' in their lies. (eg. Religions, politicians, capitalists, tyrants)

Communication is a problem, and when we 'stumble' upon 'things' we 'don't know' we can find no true sense of security from the uncertainty it my bring. So we feel lost, fearful and disconnected from others. We would rather not know, or not ask about things that might appear true to our 'heart' and stay asleep from letting our love speak for itself. 

With so much uncertainty and so much deceit from evil and confusion  in the world we can only rely on one thing that will make us realise that we are human: that we have this body, this life, and it will come and go, we will die. And the only certainty in this life is love. This love in unlimited and is homed by the soul.

The call is for the soul of man to
be awoken from this clouded state in our complicated existence. Our woozy eyes shall be opened to the truth. We will be able share with each other our way of life 'lend me our eyes' and we can see what we can change but we must stay true to ourselves and not settle for one mode of existence we must keep our 'soul... totally free'. We will find trust, honesty and peace because, (see "sign no more": 'love it will not betray you dismay or enslave you, it will set you free'), and just like we faced the birth into this life, we will face it's end, we will 'meet 'our' maker'.