How do we know that we truly comprehend and understand the whole truth about the incarnation?
Firstly, every thing we believe must be internally present and externally proved. Jesus said that by their fruits you shall know them. If we believe that theft is unethical than we should not steal. I it pure hypocrisy to say we are compassionate Christians whilst we refuse to stop and see if the old lady on the side of the road needs help.
That said let us define what the "whole truth" about the incarnation is.
When God created the world He did it through speaking the word, and in the beginning the word was with God and the word was God and the word became flesh and descended to the earth it had created for to redeem the object of it's grace. Christ was fully man and fully God. This is called the "hypostatic union". It is the conjunction of the immortal God and the mortal body of a man.
If we are to"incarnate"our thoughts into practical application then we must ask forgiveness of Christ our mediator, have faith in his power to regenerate us and work out our salvation through faith in good works(which we are now able to do thanks to the incarnation)