Does the following passage mean that there is no Satan or demons that cause men to do evil?:

"He summoned the multitude, and said to them, "Hear, and understand. That which enters into the mouth doesn't defile the man; but that which proceeds out of the mouth, this defiles the man." Then the disciples came, and said to him, "Do you know that the Pharisees were offended, when they heard this saying?" But he answered, "Every plant which my heavenly Father didn't plant will be uprooted. Leave them alone. They are blind guides of the blind. If the blind guide the blind, both will fall into a pit." Peter answered him, "Explain the parable to us." So Jesus said, "Do you also still not understand? Don't you understand that whatever goes into the mouth passes into the belly, and then out of the body? But the things which proceed out of the mouth come out of the heart, and they defile the man. For out of the heart come forth evil thoughts, murders, adulteries, sexual sins, thefts, false testimony, and blasphemies. These are the things which defile the man; but to eat with unwashed hands doesn't defile the man."" (Mark 7:10-20).

When the paper mentions that a truck ran over a man and killed him, does it mean there was no driver? Because one piece of a puzzle is mentioned in one passage, you cannot conclude that all other related piece are now non-existent. The Bible is quite clear that Satan exists. Job 1 and Matthew 4 are two prime examples.

Jesus is stating that corruption is internal, not external. Sin doesn't reside in physical things. Sins come from within because of the choices a man makes. Satan is external. He cannot make you sin, but he certainly encourages people to sin by making sin appear to be alluring. The choice, however, remains personal.

James talks of the same. "Let no one say when he is tempted, "I am tempted by God"; for God cannot be tempted by evil, nor does He Himself tempt anyone. But each one is tempted when he is drawn away by his own desires and enticed. Then, when desire has conceived, it gives birth to sin; and sin, when it is full-grown, brings forth death. Do not be deceived, my beloved brethren" (James 1:13-16). Satan is the source of enticement. He uses as his material our own natural desires to manipulate us into doing wrong.

See also:

Questions and Answers regarding Sin
Questions and Answers regarding Temptation
The Nature of Sin, Temptation, and Lust