You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <backlinks gblcontinue="0|Main_Page|38" />
  </query-continue>
  <query>
    <pages>
      <page pageid="4" ns="0" title="Machismo" contentmodel="wikitext" pagelanguage="en" touched="2016-07-27T18:11:49Z" lastrevid="5666" counter="21740" length="1370" />
      <page pageid="5" ns="0" title="Era de la Gracia" contentmodel="wikitext" pagelanguage="en" touched="2016-07-27T17:21:18Z" lastrevid="5592" counter="19333" length="768" />
      <page pageid="18" ns="0" title="Tiempos actuales" contentmodel="wikitext" pagelanguage="en" touched="2017-05-13T01:39:27Z" lastrevid="6624" counter="26919" length="4670" />
      <page pageid="19" ns="0" title="La Marca de Dios" contentmodel="wikitext" pagelanguage="en" touched="2016-07-27T17:49:24Z" lastrevid="5625" counter="37684" length="7162" />
      <page pageid="21" ns="0" title="La Majestad de Dios" contentmodel="wikitext" pagelanguage="en" touched="2016-07-27T17:49:03Z" lastrevid="5623" counter="7526" length="855" />
      <page pageid="24" ns="0" title="La Resurrección" contentmodel="wikitext" pagelanguage="en" touched="2018-09-08T22:35:52Z" lastrevid="7831" counter="14950" length="3081" />
      <page pageid="25" ns="0" title="La Sangre de Cristo" contentmodel="wikitext" pagelanguage="en" touched="2016-07-27T17:54:50Z" lastrevid="5635" counter="17219" length="1994" />
      <page pageid="26" ns="0" title="¿Cuándo Principió “El Hijo”?" contentmodel="wikitext" pagelanguage="en" touched="2016-07-27T18:39:18Z" lastrevid="5702" counter="4001" length="847" />
      <page pageid="29" ns="0" title="La Humanidad del Señor Jesús" contentmodel="wikitext" pagelanguage="en" touched="2016-07-27T03:10:47Z" lastrevid="5529" counter="12324" length="2780" />
      <page pageid="37" ns="0" title="El Poder del NOMBRE" contentmodel="wikitext" pagelanguage="en" touched="2016-07-27T03:12:18Z" lastrevid="5530" counter="13990" length="3225" />
    </pages>
  </query>
</api>