The resolution to this question might come down to two things: What evidence do you find the most compelling and what kind of belief do you have about human nature. Either one or a combination of both could end up answering the question in a persuasive way. I think that it's impossible to answer it without either, though. Hence the first thing you will have to do is acquire as much evidence on both sides. I think it's a plentiful enough topic to do so. As for the second part, I will try to lay it out to you. The most important thing to know is that like most pressing and powerful questions that are worthy of exploration, there is not a "right" answer as much as there is a "defensible" one. Approach it like this and I think your investigation will hold more value.
If you believe that human nature and human impulses generally turn out for the best, you will side with genetic engineering being a good thing. You will be persuaded by the possibilities and promises of what can be done. In the field of plant research, crop development, and medical science, genetic technology will be compelling to you because of the empowerment of the human mind and its capacity. You will believe that any tool that can allow scientists to develop greater harvests of fruits and vegetables can help to eliminate world hunger. You will believe that developing different species of plants can have unlimited positive benefits. You will believe that any engineering that can bring scientists closer to a cure for diseases such as cancer, AIDS, or Alzheimer's is worth not merely investigating, but pursuing. You will believe this because, if you believe in the inherently good nature of human beings, you will presume that genetic engineering/ technology will be in good hands, guided for good uses and steered from bad ones.
I think you know where the next side is going...
If you believe in the nature of humans to be one where good intentions end up going astray, or believe that human impulses are not above corruptibility and corrosion, you would probably side against genetic engineering. You would perceive this to be the case because you would feel that this branch of science/ technology is too much power for human beings to possess. You might feel that this brings humans too close to the realm of the divine and that power is not meant for us to harness. If humans had the ability to control the elemens of the divine or the natural world, unlimited power is not far behind and this scares you because of your perception of human impulses not being inherently good. At the very least, you would point out that humans can make a mistake and end up doing more damage than originally intended because the power of genetic engineering is sweeping and broad in scope. Due to this, you would be wary of empowering humans to this degree. If you felt that human impulses have a penchant to be corrupted, you would recoil in horror at humans developing this technology and then turning around to selling it to the higher bidder. Essentially, you would be afraid of giving humans this much power and would feel that the natural checks provided by the realm of divine or the nature is there for a purpose: Namely to deny ours, as human beings.
The evidence that will guide you is critical. I think that this will end up playing a formative and decisive role in how you answer the question. However, underlying this is an essential view of human nature.