Francis explained himself, "The Lord created us in His image and likeness, and we are the image of the Lord, and He does good and all of us have this commandment at heart, do good and do not do evil. All of us. 'But, Father, this is not Catholic! He cannot do good.' Yes, he can... "The Lord has redeemed all of us, all of us, with the Blood of Christ, all of us, not just Catholics. Everyone! 'Father, the atheists?' Even the atheists. Everyone!" We must meet one another doing good. 'But I don't believe, Father, I am an atheist!' But do good: we will meet one another there."
The way I have seen it best expressed, is that an unbeliever might perform a good work, but not good by Divine Standards. So when the Book of Works is opened up at the Great White Throne Judgment, those works not performed through faith in Christ, will fail to meet His criterion of righteousness, and His righteous Judgment will not accept them as evidence of righteousness.
Likewise, accepting the works performed as good independent of Christ, in order to find a common ground to plant the seed, can merely exacerbate future problems.
It can promote legalism, vice grace. A person’s mind is shaped by his thinking. As we solve problems independent of Christ, we scar our soul for future problem solving. If we continue to entrench our thinking upon what is right in our own eyes, we trend towards thinking independently of Him in the future. It becomes a stumbling stone to those not yet in faith with Him.