A successful business is a team effort and not a lone mission. When there are two brains working for one business, it is much more fun and much easier.
To begin with, the business partner will help you take action and be accountable for things. If you have an idea and you know it that it is commercially viable, but you are unable to take action for the same, a business partner will help you do so. With a like minded individual you can gain a lot more momentum than you can do individually. With a business partner who compliments your skills, you can fill in for your skill gap. Such partnerships help in the creation of ideas and execution of the same. If you have plenty of ideas but are unable to execute them, a business partner might help you do so.
A business partner will create synergy. Two brains are always better than one and when two of you are working on the business, you will be able to create much more than you could individually. With a business partner, you will be able to expand your network by connecting with the contacts of your partners as well. It is much more enjoyable and rewarding to be working with a partner, but things can end up in the wrong way as well. But there are two ways to look at it, a partner will enhance your decision making, bring in synergy and help you grow your business. In contrast, you might not agree with the decisions made by your partner, you might not be ready to give any equity and you might go separate ways.
If you think you do not need a partner, then do not take one.
If you are thinking about it, but not ready to have anyone on board yet, then make sure you work together for a short period before you formally begin working on the business. Once you work with an individual, you can get an insight into his working pattern, thinking patterns and decision making, this will help you come to a decision. After working with them, if you know that this is the right person to run your business with you, only then make a legal agreement that is fair to all the parties. If you cannot trust the person, you are working with the wrong partner. When it comes to giving equity, it is better to have a partial share of the business that is growing than to hold all the shares of a business that is making no growth.
Ask yourself if you are ready to work with a partner. If you want funding, if you want to grow, a partner will help you do so. But take the right steps before you make the final offer. Many startups have had partners on board and the business has thrived. There are also horror stories about the business winding up due to the wrong partner. Choosing the right individual is important, for your business and in your life.