Eve was not content with the pleasures of the garden, with the food she was given and the knowledge and communion of the Lord. She was enticed by the devil to be like God, to have knowledge of good and evil and to feed her flesh. Men are drawn away from their wives because they are discontent with the spouse that God gave them. Giving into the temptations of lust and adultery. Wives are not content to be keepers of the home. They seek fulfillment in careers and not in the raising of children (which is one of the highest callings in life). We turn to religion using works in an attempt to find favor with God and gain our own salvation rather than be content with Jesus' finished work on the cross. I could go on but I think you get the point. All these things show a contempt for God, for His word and His desires for you.
When we are discontent we look outside of God's will for our lives to fulfill God given desires and these things lead to sin see James 1:21.
Our contentment comes down to faith. Psalm 23 The Lord is my Shepherd I shall not be in want. Trust that the Lord knows what you have need of even before you ask and be thankful for what He has already given you. Romans 1:21 explains that one of the great sins of man is un-thankfulness.
Paul exhorts us:
1 Timothy 6:6
New King James Version (NKJV)
6 Now godliness with contentment is great gain.
and the writer of Hebrews states:
Hebrews 13:5
New King James Version (NKJV)
God bless the Lord is on your side.