message to an Atheist

I don't know which teachings of Christ you hold to be good, but whichever those are, they are what Matthew refers to 6:33 in seeking "first the kingdom of God, and his righteousness."
If you suffer from hunger, then avoid doing committing evil. Do not murder, or steal from those who are suffering more than yourself.  I think that even those who hold Ahteistic views believe that it is better to die, than to treat others unjustly.
What I understand, is that if I hold to that standard of love, towards my fellow man, then I am pursuing the kingdom of God, and will hopefully be more worthy or Heaven when I die, even if I die from that hunger. Death is iminant for all of us, but if I die, avoiding evil through love, then I will live in eternal happiness.
The more we worry about these things, the more we will be tempted to do evil when we are deprived of material things. This verse is about putting things in perspective: What is truly important when times get tough? It is not saying that we need to stop working, or earning a living, or seeking justice when it is due to us. It says, "Do no worry."  It doesn't say, "Don't worry, be happy."
I think this is a difficult for everyone, when push come to shove, but I think there is a natural, situational wisdom to it.