What should I do at the Church of the Machine?

Go forward when you first get here, and Bismuth will give you a hint.

You want to create a chip.

You'll need to use the giant spider to do that.

Climb inside and take a look around.

Take some time and play around with the controls.  If you want to know how
they work, read ahead.

The icons at the bottom of the screen represent a program of sorts.  The
arrows indicate the spider's movement -- the forward arrow tells it to move
forward, the left and right arrows tell it to turn and then move forward, and
the reverse pointing arrow tell it to turn around and go forward.

The buttons in the upper-right corner change the program.  The single right
arrow moves the cursor (the glowing icon) forward one spot, the group of
arrows move it forward four spots, and the up and down arrows change the
instruction located at the cursor.

Try programming the computer and then pull the lever to see what happens.

Whenever the spider approaches one of the altars, the chip it's carrying
gains one of the three symbols.

But there's another catch -- you have to return to the center of the church
when the program reaches the chip icon.

There's no way you can get to all the altars and back in a single pass.

Fortunately, the program will repeat itself if you are in the center of the
church when the chip comes around again.

You'll want to reprogram the spider in the middle of a cycle, so that you can
pick up all three symbols in one program.

Did you notice the statues at the bottom of the church?