When God says No: A Lesson from the Decapolis

In the Gospel of Mark, we see a striking interaction where Jesus denies a heartfelt request from a man He just saved. This man arguably had the best story in the Bible—imagine what he could have done if he had traveled with Jesus!
The Setting: A Region in Fear
Jesus arrives in the region of the Gerasenes and meets a man possessed by a "Legion" of demons. After a powerful deliverance, the townspeople react with terror because of the power they witnessed and the loss of their livestock.
"Then the people began to plead with Jesus to leave their region." — Mark 5:17
The town officially rejects Jesus. They kicked Him out.
The Request: A "Good" Desire Denied
As Jesus is literally stepping into the boat to leave, the man who was just delivered makes a request that seems perfect: he wants to be a disciple.
"As Jesus was getting into the boat, the man who had been demon-possessed begged to go with him." — Mark 5:18
But Jesus said no. Even though it was a good thing to want to follow Him, Jesus refused.
"Jesus did not let him..." — Mark 5:19a

Jesus returned to this same region some time later. In Mark 5, they kicked Him out. But look at the response when He comes back in chapter 7.
"Then Jesus left the vicinity of Tyre and went through Sidon, down to the Sea of Galilee and into the region of the Decapolis." — Mark 7:31
This time, the town isn't angry. They aren't pleading with Him to leave. Instead, they are bringing the sick and the lame to Him.
"The people were amazed when they saw the mute speaking, the crippled made well, the lame walking and the blind seeing. And they glorified the God of Israel." — Matthew 15:31
What changed? Why did they go from kicking Jesus out to glorifying God and gathered in crowds of 4,000 people to hear Him?

The Answer: Obedience in the "No"
The change happened because of what the man did when Jesus told him "no" in the boat. Jesus gave the man a specific command instead of letting him come along:
"...but said, 'Go home to your own people and tell them how much the Lord has done for you, and how he has had mercy on you.'" — Mark 5:19b
This man was the "crazy demon man." He probably had family there, and he had probably hurt them. Maybe he didn't want to go back, I know I would be ashamed. The town didn't like him, and he probably didn't like them. But he obeyed.
"So the man went away and began to tell in the Decapolis how much Jesus had done for him. And all the people were amazed." — Mark 5:20
The man stayed behind and became the only "Jesus" that region would see for a long time. He went through all ten cities (the Decapolis) telling his story. When Jesus finally returned, the people were ready to receive Him.

Personal Example
I have had this happen to me in a way
I have heard God twice in my life. Once when I was a teen I had been mistreated at work in a variety of ways and went to quit my job. As I got to the door handle to talk to my manager, God said:
No.
I was in disbelief, because I had every right to quit. But again, He told me no. He didn’t explain anything to me. A few weeks later, I ended up having a heart attack from the stress at the job and had to quit anyway. He did not stop me then. I struggled with it for a while and truly did not understand why He put me through that. But because of how life turned out afterward, I ended up meeting my beautiful wife @Mariah [CoHead of Bible Studies] . Had I not listened, I may have missed out.