Psalm 46:10 tells us to, "Be still and know that I am God." The implication here is that if we are never still that we will really never know God in the way that He intended. This puts a very high premium on being still before God.
Jesus put it another way when he was visiting with Martha and Mary. Martha was an angry, overworked woman with a lazy sister who would not get up to help even when the Son of God came over for lunch. It is funny that Jesus came to Mary's defense saying, "...you are worried and upset about many things, but only one thing is needed. Mary has chosen what is better, and it will not be taken away from her."
We act on what we actually believe, not on what we say that we believe, which may be something else entirely. If we really believe what Jesus was saying, we will put knowing Him above serving Him because we believe that He wants a relationship with us more than he wants what we can produce by working hard for Him.
What I am trying to say is that being still starts with stopping, even if our busyness is due to church activities or helping the poor, or any other good works. We have to stop in order to be still enough to get to know God. This entire line of thought is based on the assumption that God wants to get to know us, and that He wants to spend time with us.
How can I really know that God wants to spend time with me? Doesn't the fact that I am so far less than perfect in my execution of the Christian walk cause Him to distance Himself from me? No, it does not.
Revelation 3:20 tells us that Jesus stands at the door of our hearts and knocks. He wants us to be listening for His call, to respond to His voice, to open up our hearts and to fellowship with Him. This verse is often used as a proof text with the unsaved by eager evangelists, but it was actually penned to the Laodicean church by John the Apostle. This particular church was very backslidden, and Jesus gave them several warnings. He called them lukewarm, needy and blind. Part of the answer to their problems was simply that they needed to see themselves as they were, and repent. Jesus was pursuing them while they were still all messed up. He pursues us all the time, not just when we are doing well, but all the time.
If we just stop long enough to be still, we can begin to be in a place where we can hear His voice. We start by just believing that our God wants a relationship with us, and waiting for Him.