When you first accept an applicant as a tenant you do so with the understanding that they're going to abide by the contract that you have both signed and that you will provide them with full access to the property that they are renting from you. If you have not been in the rental business very long, it's entirely possible that you've only come across those fantastic tenants that meet all expectations. They pay on time, keep the property clean and picked up, and let you know if anything needs to be fixed before it becomes a disaster.
If you've done your due diligence and screened each tenant carefully you should have more good tenants than bad, but there may be times when a tenant looks great on paper but turns out to be entirely different once they are in the unit. Sometimes differences between landlords and tenants can be hashed out between them, but when it comes down to rent not being paid or destruction to the property, it may be time for an eviction.
Evictions are rarely easy, especially if you are a single landlord trying to protect your property. There are times when a tenant may lash out and cause more trouble than they did to begin with, but you'll need to make sure everything is very well documented and that you follow the law to the letter. If you don't, the process may start over again and you'll continue to lose money.