In this quote, William Edward Hickson is suggesting that one should be bold and courageous in order to win the heart of a reasonable girl. The phrase "faint heart" refers to somebody who does not have courage or is easily dissuaded. The ramification is that if one is timid or reluctant, they are unlikely to prosper in matters of love.
This quote might be interpreted more broadly as well, as a call to action in any circumstance where one desires a favorable outcome. It suggests that a person need to be willing to take threats and put themselves out there in order to accomplish their goals, whether in matters of the heart or in other locations of life.
Overall, the quote can be seen as an encouragement to be brave and vibrant, and to not let worry or doubt hold us back from pursuing our dreams and desires.