"Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you?" (1 Corinthians 3:16)
We are the temple of God and Holy Spirit dwells in us. God takes it very serious if His temple is desecrated and dishonored with worldly things. If God's temple is desecrated He will destroy those who have desecrated it. When God gave woman to Man, the man, Adam said "This is now bone of my bones, and flesh of my flesh: she shall be called Woman, because she was taken out of Man. Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh". (Genesis 2:23-24) If a man joins his flesh with another woman, obviously, he is becoming one with her and both have defiles their bodies.
"Know ye not that your bodies are the members of Christ? shall I then take the members of Christ, and make them the members of an harlot? God forbid. What? know ye not that he which is joined to an harlot is one body? for two, saith he, shall be one flesh" (1 Corinthians 6:15-16)
Jesus cast out all them that sold and bought in the temple. People who came to the temple to worship God used the porch for wrongful purposes and sold merchandise. They did not consider it profane to allow merchandise in the premise of the temple inasmuch as it was easy for them to buy things used for worship and sacrifice, yet on the whole the trade and transactions gave rise to great deal of noise, confusion and disturbance to the true worshippers. This place was also used by money exchangers to convert Jewish coins in to Roman coins which gave rise to much noise and confusion. This place was also used for selling doves, which are, of course, used as sacrifice elements during worship, yet the scene produced a great deal of noise and confusion. Therefore, Jesus over threw the tables of money changers, and the seats of those who sold doves. They made the house of prayer into a den of thieves.
Even them will I bring to my holy mountain, and make them joyful in my house of prayer: their burnt offerings and their sacrifices shall be accepted upon mine altar; for mine house shall be called an house of prayer for all people. (Isaiah 56:7)
"And Jesus went into the temple of God, and cast out all them that sold and bought in the temple, and overthrew the tables of the moneychangers, and the seats of them that sold doves, And said unto them, It is written, My house shall be called the house of prayer; but ye have made it a den of thieves" (Matthew 21:12-13)
The merchants misused the porch and the temple area for selling their merchandise thinking that those who need them for worship may use them and this place would be an easy access to them, yet the problem that such merchandise and the transactions within and without the temple area disturbed the worship service, and caused great deal of confusion within the temple.
Much of that devotion that was needed was diverted to the peripherals and a secondary importance was given to worship, whereas it should have received the primary importance. When a diversion from the worship takes place to give importance to peripherals it becomes idolatry. God does not like His place to be taken by peripherals, no matter how attractive they look like. It was, therefore, Jesus overthrew the tables of money changers, the seats of them that sold doves and cast all of them out of temple.
"If any man defile the temple of God, him shall God destroy; for the temple of God is holy, which temple ye are". (1 Corinthians 3:17)