Trust me with regard to the fact of I [being] in the Father and the Father in me, but, if not, through the self-same work trust [me].
Jhn 14:11 Believe me that I [am] in the Father, and the Father in me: or else believe me for the very works' sake.
Interesting and Hidden Aspects:
Christ recognizes that we cannot understand what it means for Christ to be in the Father and the Father in him. He asks that we trust that this is true, but if we cannot understand it, he gives us another path to understanding: that they are doing the same work.
The meaning of this phrase revolves around the Greek word "autos." This is the word from which we get "automatic", but it is usually translated as some form of "self". Our idea of "automatic" comes from the description of machines as "self starting" or "self running." However, the Greek concept is quite a bit deeper than our casual (on often incorrect) use of a reflexive pronoun.
The meaning of the Greek auto is literally "the same." However, over time, it came to mean "one's true self." We get a sense of this in English with the phrase "self-same." It is the same as itself. Autos also has a sense of "the soul" as opposed to the body. It carries our personal consciousness and accord, that is the self acting "of one's own accord."
So when Christ says that he and the Father are doing the "same" (autos) works, it means that they are sharing the same will, the same accord on what is to be done.
πιστεύεις "Believe" is from pisteuô (pisteuo), which means "to trust, put faith in, or rely on a person", "to believe in someone's words", "to comply", "to feel confident in a thing," and "to entrust in a thing."
εἰ δὲ μή "Or else" is from the phrase ei de me, which means "but if not" "If" is from ei, which is the particle use with the imperative usually to express conditions "if" or indirect questions, "whether." "But" is from δὲ de (de), which means "but" and "on the other hand." It is the particle that joins sentences and an adversarial way. "Not" is from mê (me), which is the negative used in prohibitions and expressions of doubt meaning "not" and "no."
αὐτῷ "Sake" is from autos (autos), which means "the same," and the reflexive pronouns, "myself", "yourself", "himself", "herself", "itself," or the oblique case of the pronouns, "him", "her," and "it." It also means "one's true self," that is, "the soul" as opposed to the body and "of one's own accord."