Mankinds greatest problem. [Romans 3 v 10 -23 ]

I was preaching last Sunday ,and my first point was mankinds greastest problem ,the answer is sin, yes sin, modern man has left this out of the reckoning,but scripture declares it continually,and mans behaviour manifests it.  A survivor of  Auschwitz death camp, was asked,what he had learned, his answer was,/ I think Im only sure of one thing, nobody knows themselves/ ,he went on to say,/ The nice person you meet on the street, you ask ,where is North street? and he goes with you, and shows you,and is nice and kind.That same person in a different situation could be the worst sadist. Nobody knows themselves. Sometimes when somebody is really nice to me I find myself thinking, How will he be in Sobibor?[ or Auschwitz].Just recently Anders Breivik was found guilty of murdering all those dear young people, and also planting a bomb, that killed other people.  He smiled when he was told he was sane, and then apologised for not killing more people, yes he is sane ,but he is an insane sinner. The word of God gives a chilling summary of man condtion in Romans 3,and it sums it all up in v23, for all have sinned and come short of the glory of God,the root of it all is declared in Jeremiah 17 v9, /the heart is deceitful and desperately wicked,/  and then it adds ,/who can know it?/,the words of that survivor fom Auschwitz ,have a biblical truth to them,/nobody knows themselves/. Only God knows the human heart, its potential for evil, and only God has the answer to our greatest need,read Isaiah 53, of the one who was wounded for our transgressions, even Jesus, only through his death on the cross can we be forgiven and changed.
A  prayer...../Dear God thank You that through Your dear  Son Jesus You and You alone have provided the answer ,to mans greatest  problem ,our sinful nature,Amen/