We Christians certainly understand our sins. We understand we fall short of the ideal. We also understand we help each other work toward being Christlike, and reach out to others not of our faith in the process.
It was Christians that helped the poor in ancient Rome, that protected babies. In ancient times infanticide was prevalent. Don't want the kid, throw it out. Not just Rome, but this was practiced throughout the world. Christians stopped the practice.
During the plague in the middle ages, the sick and dying were helped by Christians organizing to do so.
Also during the Dark Ages, when western civilization fell apart, all the knowledge of the time was saved (recommend "How the Irish Saved Civilization" by Caldwell).
Monasteries formed centers that provided education and agriculture to the people.
Hospitals were created by Christians organizing to build these.
The fight to end slavery, a practice accepted world wide at the time, was opposed by Christians, led by Wilberforce. The end of slavery in the US, the underground railroad, organized by Christians.
The Suffrage Movement was begun by Christian women organizing.
The Civil Rights movement of the '50's thru '60's organized by Christians, led by Martin Luther King, a Christian minister.
I remember an interview with an atheist in the aftermath of Katrina, saying he had to hand it to Christians; they turned out in droves to help. Atheists didn't organize to help or raise money.
Currently millions of Christians worldwide are helping the sick, feeding the poor, with massive amounts of people and money helping AIDS patients in Africa. Christians are providing millions of dollars reaching out to the less fortunate. Thousands of Christians are on the scene, sacrificing their time and bodies to help.
All these good works, and the danger and sacrifice, is the result of Jesus Christ, God entering our world, and being an example of right and righteous living that is the foundation of all these good works.
It would be nice if this year atheists would let us have our celebration of our Lord's birth, without the nastiness of bigotry, intolerance and lies. As shown in these accomplishments, much good has been done by Christians. What good has atheism brought to us? Nothing, because they have nothing to offer, and when there's nothing to offer, there can only be the tearing down of what is good.
We're not asking Atheists to believe, just be nice for a change. You've benefited from all that Christian's have accomplished, we pose no threat. Just let us sing our praises, worship, and do our good works.