In business, a logo is what separates one brand from another. A logo also is the brand's identity. When you see a logo, you know instantly so much about the organization. You can also recognize the brand just by seeing a logo.
Can Churches take anything from this? Our identity obviously is supposed to be in Christ. However, each individual congregation takes on its own personality, in a sense. In order to stand out, a logo becomes a graphic representation of the organization (in this case, your Church congregation). Logos can have text or have no text, but in a Church's case, you would want to have your Church's name in order to help people recognize your Church.
In short, you don't need to be concerned about whether you should or shouldn't have a logo. Instead, you can take this concern to God in prayer. However, to answer the question, a logo is just a graphic representation of the Church, so it shouldn't be a moral issue but rather a question about your Church's preference. Just keep in mind that even plain text can be a logo because there doesn't have to be an image within the logo.