If you have the world's best sales process, technology, worksheets, playbooks, sales scripts, and marketing collateral, you will still fail if you don't have the emotional strength it takes to sell.
A while back, I had a conversation with Jeff Keller, author of the bestseller Attitude Is Everything. He described the seven emotions that top salespeople must cultivate, which I've presented here as a set of daily promises:

1. I will be patient.

Customers make decisions at their own speed. Pushing customers to buy is like pulling on seedlings to make them grow. While I am always ready to help a customer, I refuse to become frustrated when they don't buy as quickly as I'd like.

2. I will be committed.

Customers respect that I'm willing to do whatever it takes (legally and ethically) to make both my customers and myself successful. I will follow through on every commitment I make, large or small. I will not give up until it's clear that I cannot help my customer.

3. I will be enthusiastic.

Because enthusiasm is contagious, I will be enthusiastic about myself, my firm, my product, and my customers. To remain enthusiastic I will draw on my desire to help people improve their lives and thereby create greater wealth and success for everyone.

4. I will be curious.

Selling means being alive to the mysteries and puzzles of life. Every customer and every situation is different and has something important to teach me. I will keep my ears and eyes open to any knowledge that can help me better serve my customers.

5. I will be brave.

I will have the courage take the risks necessary to expand myself and my business, even in the face of enormous odds. I will not sacrifice my ambition to achieve a false sense of security. I will not take the easy path when I know that the thorny path will take me to my goal.

6. I will be forthright.

I will not have a hidden agenda that separates my stated purpose from my true motivations. I will be honest with my customers and colleagues, even when it's to my disadvantage. I will never use manipulative tactics to trick customers into buying.

7. I will be flexible.

Life is all about change; nothing stays the same. I will be flexible so that I can observe what's working and what's not. I will change my approach to match changing circumstances. I will adapt so that I can better meet my customer's need.