“And without faith it is impossible to please God, because anyone who comes to him must believe that he exists and that he rewards those who earnestly seek him” Hebrews 11:6
But without faith it is impossible to please him – Without “confidence” in God – in his fidelity, his truth, his wisdom, his promises. And this is as true in other things as in religion. It is impossible for a child to please his father unless he has confidence in him. It is impossible for a wife to please her husband, or a husband a wife, unless they have confidence in each other. If there is distrust and jealousy on either part, there is discord and misery. We cannot be pleased with a professed friend unless he has such confidence in us as to believe our declarations and promises. The same thing is true of God. He cannot be pleased with the man who has no confidence in him; who doubts the truth of his declarations and promises; who does not believe that his ways are right, or that he is qualified for universal empire. The requirement of faith or confidence in God is not arbitrary; it is just what we require of our children, and partners in life, and friends, as the indispensable condition of our being pleased with them.
For he that cometh to God – In any way – as a worshipper. This is alike required in public worship, in the family, and in secret devotion.
Must believe that he is – That God exists. This is the first thing required in worship. Evidently we cannot come to him in an acceptable manner if we doubt his existence. We do not see him, but we must believe that he is; we cannot form in our mind a correct image of God, but this should not prevent a conviction that there is such a Being. But the declaration here implies more than that there should be a general persuasion of the truth that there is a God. It is necessary that we have this belief in lively exercise in the act of drawing near to him, and that we should realize that we are actually in the presence of the all-seeing Jehovah.
And that he is a rewarder of them that diligently seek him – This is equally necessary as the belief that he exists. If we could not believe that God would hear and answer our prayers, there could be no encouragement to call upon him. It is not meant here that the desire of the reward is to be the motive for seeking God – for the apostle makes no affirmation on that point; but that it is impossible to make an acceptable approach to him unless we have this belief.
(From Barnes Notes on the bible)