The likely answer, as Keith and others suggest, is that if you've only received 1 offer in 3 months, then your home is priced too high. Ask your agent for a CMA. Then, not only study it yourself, but ask your agent to take you to see the other active listings that are comps. Compare them yourself. Put yourself into the shoes of a potential purchaser. Evaluate location, price, condition, and so on.
There are other possibilities, of course. As others asked, are you a FSBO or are you listed with a Realtor? Nothing wrong with being a FSBO, but your marketing may not be as effective. And if you're a FSBO, make sure that, if you're willing to provide the buyer's agent a commission, that you make that clear in your marketing.
It's also possible that your home doesn't show well. After you've completed the exercise I suggested above (actually visiting the comps), compare their appearances to your home's. Again, put yourself into the shoes of potential buyers.
You didn't mention whether you'd had many showing. If you've had a lot of showings, that's an indication that your agent (or you, if you're a FSBO) is doing a good job of marketing, and that the price is reasonable. People are showing up because they're looking to buy a home of your approximate size in your approximate location for approximately what you've listed it for. Then, if they aren't making offer, it means that something's turning them off once they see the house. Frequently, it's the condition.
On the other hand, if you've had very few showings, then either the marketing is faulty or the price is too high, or both. Either people don't know about your house, or they do know but consider it to be a poor value.
So, get a CMA. Then tour the other comps.
Hope that helps.