It's important to renew our minds, but it's also important to realize that this process of reprogramming or renewing our minds will take place little by little. Don't be discouraged if progress seems slow. Don't get down when you have setbacks or bad days. Just get back up, dust yourself off and start again.
When a baby is learning to walk, he falls many, many times before he develops the ability to walk without falling; however, the baby is persistent. He may cry for a while after he falls down, but he always gets right back up and tries again.
Learning to change our thinking works the same way. We struggle and fall down, but God is always there to pick us up. Rather than get frustrated, you should, as the Bible says, "triumph" in your hardship, because the very fact that you're struggling means that you're fighting the good fight.
There will be days when we don't do everything right, days when our thinking is negative. But never stop trying. God is gradually bringing us around to His way of thinking. Just don't give up!
Romans 5:3 - Not only so, but we also glory in our sufferings, because we know that suffering produces perseverance
Prayer Starter: Lord, thank You for picking me up when I fall down. I know that my struggles mean that You are helping me overcome my negative mindsets and bringing me more and more in line with Your way of thinking.