How can we eliminate the extra space in the pdf when including two tex files such that they are continuous in page?

Question

I had two separate tex files ( theory.tex & molecular_dynamics.tex ) for chapter 2, where i had some written text in these tex files, and are included in a single tex file named main.tex whose working directory is as shown below:

On compiling this main.tex file, i get the end page of theory.tex file containing blank spaces(shown in attached screenshot) and the page of molecular_dynamics.tex file starts from new page (shown in attached screenshot) rather being continuous from the same page, not in next page, where the last page of theory.tex file ends. Is there any command that makes continuous text between these two included files? However i want the usual format when it jumps to new chapter.

\documentclass[a4paper,12pt,oneside]{book}
\include{packages/packages}
\begin{document}
\include{ch2/theory/theory/theory}
\include{ch2/theory/molecular_dynamics/molecular_dynamics}
\include{ch3/results1/results1}
\include{ch3/results2/results2}
\end{document}