How do we understand it when Christ says that apart from Him we can do nothing (John 15:5)? I once had an experience that helped me understand this.
I was involved in a discussion with the elders about whether some of the things I had done on the worship team were too charismatic. It had not gone as I wanted it to go. They encouraged me to continue on the worship team, but within certain boundaries. Now I did not regard the boundaries themselves to be that big a problem. But I was concerned that the issue would be divisive in the congregation, which had various opinions on charismatic issues. However, I enjoyed being on the worship team. So I convinced myself that the discussion was not over and I could still manage to convince the elders to see my point of view. The bottom line is I am stubborn and sometimes God has to do something to get my attention.
Often on the worship team I would feel the power of God flowing through me. That morning what I felt was God slowly pulling His power out. It was like God was giving me just enough for that morning . At the end of the service I felt like a dead battery, sucked dry of its last reserve of current. I had never felt a more desolate feeling in my life. I do not believe God personally ever left me, but any feeling of His power working through me was gone. I do not know if this is how King Saul felt, but if it was and it was permanent, I am not surprised he went crazy, even ignoring the help of a demon (see 1 Samuel 16). One of the elders, a very sensible man, when I said I was considering resigning from the worship team, suggested I wait a few weeks and see if I still felt that way. But there was no way I was going back up on that platform. Not without His power. Now do not get me wrong; I am sure if I gritted my teeth I could have physically walked up on the platform. But I do not know and do not want to know what the results would have looked like.
I am convinced the presence of the Holy Spirit is always with the genuine believer in Christ (Romans 8:9; 1 Corinthians 6:19) and is at work in them to transform them into who God wants them to be (2 Corinthians 3:18; Philippians 2:13). But He also gives power to meet specific situations (Acts 4:23-31; 13:9-12). Now you cannot prove doctrine from personal experience, but I feel mine does illustrate the fact that apart from Him we really can do nothing. And while my feeling that God is working through me has returned since I resigned, this puts in perspective the times I simply feel dry and am not aware of God working through me as strongly as normally.