Speaking Lightly of Sin

I am listening to "Guard Your Heart" as sung by Mac Lynch on the cd My Son Give me Thine Heart. In the song it states "never ... speaking lightly of our sin." I wonder where would the Church and even our country if we as Christians would not speak lightly of our sin; whether with each other or even as internally we excuse our sin. I have been reading portions from the gospels and the OT Prophets and I keep finding the recurring emphasis on any sin is to much. Now I know that none of us will be perfect until we see Jesus Christ face to face however, Paul has taught us in 1 Corinthians 5:6 that any hint of leaven (sin) leaveneth (makes the whole sinful) the whole lump of bread dough. We must be on constant guard to prevent any sin from entering our lives and taking root defiling us entirely. Guard Your Heart