Who gets better access to these resources? Thomas Malthus proves that in an environment with limited resources causes competition towards these resources. This is called natural selection. Natural selection is not at random, and it's specifically targeted at those whom are not fit for certain environments.
Now Darwin could have learned about Thomas Malthus' hypothesis on natural selection. However without Malthus, Darwin would have thought that populations grew until they were aligned with their resources. Without Thomas Malthus, it would have probably taken a while for Darwin to come across Malthus' idea on natural selection with limited resources, but eventually I'm sure he would have came to the conclusion
The attitude the church had towards Darwin's view on evolution and natural selection struck up an anti-revolution against his publication of his book, Origin of Species. (http://biologos.org/questions/christian-response-to-darwin) The link given shows the Christian's reaction towards his book because it completely went against Catholicism due to the controversy of creation and evolution. Overall with the help of Thomas Malthus, Darwin is and forever will be known for his work on evolution.