Should we still be fruitful and multiply or should we try to prevent population growth which would ultimately result in the starvation of billions if mass disease does not kill them off first?
Your conclusion is based on a hypothesis that resources and specifically food will always be stagnant at today slevel or increase at a slower pace than human population growth. The answers are more based on your political affiliation which decides your world view, scientific view and social views.
I totally disagree with this Malthus hypothesis.
In Europe/USA/Latin America there is abundance of food. There is more forest area today than there were 100 years ago in USA and Western Europe. There are many factors for why I'm optimistic about the future and higher population, but here are the first 10 I can think of.
(1) more than 95% of the population suffering from starvation lives in totalitarian/authoritarian governments.
(2) The problem of starvation is political problem due to the ineffeciency, corruption, kleptocracy of communist/totalitarian governments
(3) There is huge and incredible areas suitable for agriculture today in Africa that can make the continent self suffiecient and even export food. China knows this which is why they are trying to make the corrupt totalitarian regimes of many African states develope their agriculture.
(4) I just watched a BBC special yesterday that in Western Europe 50% of all the food is wasted before it is consumed. With better logistics, new preservation technology and effeciency in agriculture western europe can keep on increasing production and reduce waste.
(5) Almost every person born is capable of work, again the problem is the political system of redistribution instead of growth is keeping more and more people unemployed because the incentives to create wealth and be a wage earner decreases yearly.
(6) One of the biggest factors for starvation in addition to totalitarian regimes is the protectionism of democratic regimes. Special interests wants imports tariffs which reduced investement from rich countries too poor countries.
(7) All research shows that better living standards leads too less children. 2 Generations ago it was normal for a wife too have 8-15 children in europe, now the standard is 1.5 children. So if anything we need to get busy with our wives ;)
(8) Even though increased living standards increases consumption it has the good cycle of stimulating demands and investements further increasing demands for employment, and as people get better living standard soo too they have less children.
(9) The laws of supply and demand will lead to new technologies and new syntethic materials replacing resources which supply decreases
(10) Oil and gas reserves keep being unlocked. Before people thought Norway would run out of oil in 50 years. Now they know its more than 100 years, and thats not taking all the locked reserves into account.
So overpopulation is only a problem for tyrannical regimes incapable of satisfying the people needs for food, jobs and security.
Once we get rid of all the fascist/communist/totalitarian regimes the problem will be too keep people breeding more humans :D