You believe in God, but you have to deal with people who do not, and consequently who do not care for people as you do.
Yet, you can still work with such people. Jesus told of a judge who did not fear God and did not regard people,
“Now there was a widow in that city; and she came to [the judge], saying, ‘Get justice for me from my adversary’” (Luke 18:3).
She eventually got what she wanted from the judge. It is not always pleasant to work with people like that judge, nevertheless, we share this earth with them and we should do our best to work with them.