We are a trusted partner of PayPal. As with all payment methods, donations made using PayPal are extremely secure.
There could be several reasons you're seeing a decline error message or your payment won't go through.
Please click here to see this article directly from PayPal to see why your payment could have been declined: PayPal Smart Help Article Decline Tips
Here's another link with more details: PayPal Help Guide
If you continue to experience issues with PayPal, we suggest for you to use your credit card.