In science there is a law called the law of entropy. It states that everything in the natural world over time tends toward disorder, decay and death. Essentially it's a scientific description of the curse of sin and it's effects in the natural world.
The force of death and defeat are so persistent in our world you can't afford to turn your back spiritually even for a day. This is so true when it comes to our thoughts.
Without intentional effort it's easy for our minds to drift toward doubt, unbelief and playing out the worst-case scenario. This is exactly what the enemy wants us to do, to spend our time and energy envisioning limitations, what we can't do and how we're going to fail.
Recently, while on vacation, I challenged myself to make a shift in my thinking. I realized If I'm going to go to the next level of God's blessing and plan for my life I need to plant and cultivate some new thoughts.
When I was a young boy I used to love sitting on an old, rusty tractor seat that was behind an old barn on my parents farm. Because it was shaded, many hot summer days you would find me sitting on that old tractor seat dreaming of my future. I would dream up infinite scenarios of what I wanted to do in life. I would think about all the different ways I would succeed and do something significant.
That's a good example of how God expects us to use our imagination. Instead of allowing our minds to run unchecked, dominated by past experience, our physical senses and playing out 1001 ways we're going to fail to reach our goal. I believe God wants our minds inspired by His Word, to run free with expectancy and creativity, imagining the possible ways we'll experience victory, breakthrough, and the dream in our heart.
Be sure to take time to develop a mentality for success, to dream and think of possible ways you're going to succeed in God's mission for your life. Resist and root out every thought and imagination of failure, doubt and defeat.