If you believe that the Lord God knows everything about you and you do believe in him, then you should aim to live up to this belief. You would do everything for the sake of glorifying him. When you pray, you would do your utmost to mean what you say from the heart, for he knows how sincere or serious you are. This is having faith. Your eternal life depends upon how you think, speak, and act. Now, this becomes easy once you attain union with God. But our union with the Lord can never be perfect on earth as we remain sinners. Again, our intention becomes our grace.