One of my favorite expositors is Dr. J. Vernon McGee (see Thru the Bible for more info). I greatly appreciate his ability to explain complex concepts and teachings in a plain straightforward manner. Last week I read a challenging exhortation by Dr. McGee on relying on the power of the Holy Spirit rather than our own strength (The Secret of Power). Interesting to note is that despite it's 1988 copyright, the truth of the message is timeless.
"My beloved, it is only as you and I yield and our will moves out of the way that the Spirit of God can move in and bring God‟s will to bear in our lives." -Dr. J. Vernon McGee, The Secret of Power
And the angel who talked with me came again, and waked me, as a man that is wakened out of his sleep, and said unto me, What seest thou? And I said, I have looked and, behold, a lampstand all of gold, with a bowl upon the top of it, and its seven lamps on it, and seven pipes to the seven lamps, which are upon the top of it, and two olive trees by it, one upon the right side of the bowl, and the other upon the left side of it. So I answered and spoke to the angel who talked with me, saying, What are these, my lord? Then the angel who talked with me answered and said unto me, Knowest thou not what these are? And I said, No, my lord. Then he answered and spoke unto me, saying, This is the word of the LORD unto Zerubbabel, saying, Not by might, nor by power, but by my Spirit, saith the LORD of hosts.