Humanism is a concern and focus on human beings. Both the
religious and the non-religious can care about others.
But with a religious humanism, including a Christian humanism,
the concern will first be with the god and obey the religion's
rules and perhaps converting people to the religion. Then after all
that, you might worry about the person starving to death.
With a secular humanism your first concern is with the person
starving.
A religion will always put the god first, then people, even if
the religion does care about the well being of other people. A
secular humanism goes directly to caring about the person.