What is the assertion of the “white brother in Texas” (line 315)?

The "white brother in Texas" asserts that "equality" is only a matter of time...... that King, and others, are being impatient.

"All Christians know that the colored people will receive equal rights eventually, but it is possible that you are in too great a religious hurry. It has taken Christianity almost two thousand years to accomplish what it has. The teachings of Christ take time to come to earth."

How does king counter it?