Humility is what impresses God. Pride gets between us and God, and without realizing it, we actually shut Him out of our lives.
The Bible clearly shows that our spiritual well-being is dependent upon acknowledging, with our lives, our reliance upon the revealed will of God—His Word. Pride results from arrogating to oneself something for which one is indebted and would not even have except for God's benevolence. Who gave Helel (commonly mistranslated as "Lucifer," who became Satan) his beauty? his intelligence? his position of power from which he operated? Pride perverted Helel's thinking into rejecting his dependence, and he elevated himself above God.
Now what do we have that we did not receive? Did we create ourselves? Did we create the great goal in life to be in the Kingdom of God and to be born into His Family? Did we reveal God to ourselves? Did we die on the stake for the forgiveness of our sins? Did the gift of the Holy Spirit come to us through our own agency? Did we lead ourselves to repentance? Who gave us the power to believe in the true God and in His Son Jesus Christ?
It is interesting to reflect on Adam and Eve in the Garden of Eden. Satan comes along and says to them, "You will be as God." What entered into Adam and Eve at that moment? The pride of life. The result? They rejected the revelation of God. They rejected His Word and sinned. Pride subtly elevates a man to the same level as God, which results in him rejecting the very gifts God would give him for his salvation.
So, consciously or subconsciously, the proud man—us (hopefully not as much as it used to be)—is saying that he already knows better, or has the power and ability within himself by nature, thereby subtly turning salvation into something God owes him. It becomes earned.