No!!

Testing is not merely about future proofing (although it's a really nice benefit), it's about proving that your code actually works now. By writing tests and verifying that they pass you can be sure that the code actually does what you think it does. Furthermore you can ensure that when other parts of the code changes your code still does what you think it does, which might be an issue tomorrow, next week, or in ten years.

\* note: Testing does not prove that your code is correct, only that it satisfies the conditions of the test. As with all engineering testing is only effective as the person implementing it.