Does the Bible command us to be refilled by the Holy Spirit?

You have all the Holy Spirit you need when you receive him at the point of true salvation.
Now, grieving the Holy Spirit by returning to the self-directed life, following salvation, is quite another matter.

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Every child of God is indwelt by the Holy Spirit, but there is those special times the Spirit is like a well of water springing up in our souls unto everlasting life. These times for me is when the message exalts Christ as my only hope and lays me at his feet. It is when I hear a song that is rich in the gospel and it carries my soul up to heaven. It is when I am reading his word and the Spirit unlocks the scripture that I can see more clearly. It is when in prayer God unlocks the windows of heaven and you know you have the answer.

 

This is pretty much how I take it. The Spirit abides in a saved child of God, but sometimes it is more evident that the Spirit is there. As an example, for the times when I am within my own house, there are times when a person on the outside looking in can readily tell that someone is home, and there are times where a person outside looking in isn't sure. The Spirit is much the same way.

As salzer said, sometimes the Spirit is in us like a well of water. Sometimes that well is just a dribble because we've forgotten to take care of it. Sometimes the Spirit is like a fire (after all, our God is a consuming fire) that rages within us, and sometimes the embers burn down low because we've neglected to stoke the fire through prayer, study, and meditation on God's Word. The Holy Spirit is fairly easily offended and can be driven off from us by our own actions. Otherwise we wouldn't be instructed to "quench not the Spirit."

 

A preacher at an ordination council I attended asked the candidate if being filled with the Spirit meant having more of the Spirit. The answer was no, that we are fully indwelt at the moment of salvation, and that perhaps a better way to look at being filled with the Spirit was not that we had more of Him, but that He had more of us.