A person said,
So where did Jesus say "Slavery is bad, folks, stop it now"? You and I both know he too was silent on the subject.
Jesus saw slavery all around him and even fixed up slaves for their master's enjoyment, yet he didn't think to say "Ok I'm curing this slave, but he is now free - go and do likewise, free all your slaves for no man should own another".
Jesus was primarily ministering to an enslaved people the Romans were over them. They didn't have slaves themselves they were enslaved in a manner of speaking.
Jesus did heal slaves and in particular a person who was genuinly concerned for his servant came to Jesus for the good of his servant.
Let's actully look at what it says in Matthew 8
5When Jesus had entered Capernaum, a centurion came to him, asking for help. 6"Lord," he said, "my servant lies at home paralyzed and in terrible suffering."
7Jesus said to him, "I will go and heal him."
8The centurion replied, "Lord, I do not deserve to have you come under my roof. But just say the word, and my servant will be healed. 9For I myself am a man under authority, with soldiers under me. I tell this one, 'Go,' and he goes; and that one, 'Come,' and he comes. I say to my servant, 'Do this,' and he does it."
10When Jesus heard this, he was astonished and said to those following him, "I tell you the truth, I have not found anyone in Israel with such great faith. 11I say to you that many will come from the east and the west, and will take their places at the feast with Abraham, Isaac and Jacob in the kingdom of heaven. 12But the subjects of the kingdom will be thrown outside, into the darkness, where there will be weeping and gnashing of teeth."
13Then Jesus said to the centurion, "Go! It will be done just as you believed it would." And his servant was healed at that very hour.
The centurion cared abiut his servant and jesus cared about both the centurion and the servant. Jesus cared even about those who would hear and fear his judgment so that they might excersise faith just as the centurion had.