"Immediately Jesus knew in his spirit that this is what they were thinking in their hearts, and he said to them, 'Why are you thinking these things? Which is easier: to say to the paralytic, "Your sins are forgiven," or to say, "Get up, take your mat and walk"?'" NIV translation
We see that Jesus knew their hearts and we know that He knows our hearts as well. He knows our every thought and deed. When Jesus answered their thoughts, they must have been taken aback and He gives them a simple answer.
"'But that you may know that the Son of Man has authority on earth to forgive sins...' He said to the paralytic, 'I tell you, get up, take your mat, and go home.' He got up, took his mat and walked out in full view of them all. This amazed everyone and they praised God, saying, 'We have never seen anything like this!'" NIV translation
After giving them the simple answer, Jesus also gives them the big picture and that is the fact that He has the very authority that they are questioning. It was demonstrated when the man got up and walked out as they watched. That leads us to ask the question: Why did Jesus perform miracles if His ministry was spiritual? The simple answer is that the miracles were a witness to His power and authority. It is the same today as God allows His children to do miracles such as healing, etc. but it has the same purpose as it did when Jesus walked the earth.
"Once again Jesus went out beside the lake. A large crowd came to him, and he began to teach them. As he walked along, he saw Levi son of Alphaeus sitting at the tax collector's booth. 'Follow me,' Jesus told him, and Levi got up and followed him." NIV translation
When Jesus left the town of Capernaum, He went out to the north shore of the lake which is known as the Sea of Galilee (Sea of Kinneret or Lake of Gennesaret). This is the largest freshwater lake in Israel and it is fed by the Jordan River flowing through it from north to south. There was a great road there that ran from Damascus to some of the southern seaports of Phoenicia. It was along this profitable trade route that Levi had his tax collecting station where he collected import and export taxes for the Roman empire.
In this passage, Jesus made a bold statement by calling a tax collector to follow Him. These were the lowest of the low in Jewish society and, if they could be His disciples, then, anyone could. Do you know of someone who thinks that they are too dirty to come to Jesus? If so, then, remind them of Levi and Jesus' call on his life.
We notice that Levi did not argue with Jesus about being too lowly to follow Him but simply got up and followed.