We hear him speak to us through what he has shown us of his character and purpose in the written Word. Moment by moment, our vital union with Christ, experientially, is sustained and shaped and carried by the Word of God. If you don't read the Word and memorize the Word and meditate on the Word daily and delight in the Word and savor it and have your mind and emotions shaped by the Word, you will be a weak Christian at best. You will be fragile and easily deceived and easily paralyzed by trouble and stuck in many mediocre ruts. But if you read the Word and memorize important parts of it and meditate on it and savor it and steep your mind in it, then you will be like a strong tree planted by streams of water that brings forth fruit.
Christian living means living on the written Word of God, the Bible.
In true Christian living, our relation to the Word is intentional, not haphazard. It's active not passive. We pursue it and don't just wait for it to happen. The Christian life is a joyful project that calls for energy and aim and resolve and determination. It is not coasting or drifting or something that just happens to you like the weather.