Annias and his wife sold a parcel of land and told the apostles that they were giving the complete sell price.  However, they lied and held part of the money back.  Today many of us do much the same thing.  We say we have surrendered our life to Christ yet we are holding part back.  Could be a secret sin or a habit we hold onto.  Whatever it is we need to take it and lay it down at the cross and give our whole selves to Jesus.