A realization of our sins.

Romans 3:23
......for all have sinned and fall short of the glory of God. (N.K.J.V).

Matthew 9:13
.....      'I desire mercy and not sacrifice.  For I did not come to call
the righteous, but sinners to repent.'(N.K.J.V).

When we begin to realize that each and everyone of us are sinners' it's a shock to the system.  It's something that we never thought of before.  How could we be sinners if we never stole from anyone, we didn't murder anyone and we were kindhearted etc?  But in the eyes of God each and everyone of us are sinners.  Romans 3:23 says:  ...........for all have sinned and fall short of the glory of God.
Now underline All, not just some but All.   To bridge that gap between us and God we need to to admit to God our sins and ask forgiveness for all we that we have done wrong.  But we also 
needed an advocate, and God's love for us was so real, that while we were still sinners God sent his one and only Son to die on the cross. (Romans 5:8), and to take upon himself our sins.  Yes, we are 

all sinners, but God is willing to forgive us.  He wants us to come before him and admit our sins.(Matthew 9:13).  It is through God's mercy we are saved.  Are you grateful for God's mercy and forgiveness?  I know I am.