"Do you not believe that I am in the Father and the Father in me? The words that I say to you I do not speak on my own authority; but the Father who dwells in me does his works."
Here Jesus manifests His total unity with His Father. For although He Himself is God and has the power to perform great miracles, He has taken on human form and relies on the power of the Father dwelling within Him.
Here's the beauty of it: if Jesus, as a human being, can do wondrous works, so can we! He offers this same oneness with the Father to each of us, if we come, through Him, to the Father. Just imagine what the world would be like if we allowed God the Father to dwell in us and work through us as Jesus did: no challenge in life would be too great to overcome, no sorrow or cause for anger would steal our peace, no person would be too difficult to love, no shortcomings would get in our way. The saints are a model for us of what this would be like. Think of Mother Teresa, one woman who touched so many lives and conquered her human selfishness to love the unlovable, the dead and dying in India. It was the Father living in her who did these works, because in every person she helped, however loathesome their outward appearance, she saw Jesus.
We're not in India (obvious observation of the day! =D) but we still have shortcomings, challenges, and people in our lives that are not easy to love. Personally, I got to a point in studying for my finals when I had to say, "Lord, I have no motivation to study. I can't do it even though I want good grades. Help me to find the strength to do it out of gratitude for the intelligence and education You've given me, as an offering to You." My sister in highschool told my Mom and me the other day that by the end of one of her classes she's so tired of the annoying people in her class that she wants to call home even if only to hear the answering machine. My Mom told her: pray! What a gift we have that wherever we are, even in school, we can "call" our Father, or talk to Jesus' and our Mom, and we'll never get the answering machine, They always pick up. And whether we feel too weak to do what we have to do, or even if we're strong and think we can do it on our own (like Jesus), by calling on the Father and seeking His will we can do even greater things for His glory, which are everlasting,rather than our own,which is passing.
"Truly, truly, I say to you, he who believes in me will also do the works that I do; and greater works than these will he do, because I go to the Father. Whatever you ask in my name, I will do it, that the Father may be glorified in the Son; if you ask anything in my name, I will do it."