Lloyd-Jones, preaching on this text:
The trouble I find with psychology is that it is simply an attempt to give you quiet nerves instead of giving you a quiet heart. I want to be fair to psychology. It can give us, up to a point, quiet nerves, but that is not what we need--we need a quiet heart. Thank God for something that, as far as it goes, can give us quiet nerves, but do you want to be at rest on the surface or do you want to be at rest in the very depths and vitals of your being?--Martyn Lloyd-Jones, Let Not Your Heart Be Troubled (Crossway, 2009), 23
It is at this point that the gospel claims that it, and it alone, can meet and satisfy our deepest need, and here in John 14 we are told exactly how it does that.