If our body is the church, why should we go to a place called church? In the old testament days, God asked Moses to construct a place for Him to reside.

Exodus 25:8 (NKJV)
And let them make Me a sanctuary, that I may dwell among them

But in New testament, We read that our own body is the Temple of Holy Spirit.  We read it in a number of places when Paul writes to the Corinthians,

1 Corinthians 6:19 (NKJV)
Or do you not know that your body is the temple of the Holy Spirit who is in you, whom you have from God, and you are not your own?
1 Corinthians 3:17 (NIV)
If anyone destroys God’s temple, God will destroy that person; for God’s temple is sacred, and you together are that temple.
1 Corinthians 6:19 (NIV)
Do you not know that your bodies are temples of the Holy Spirit, who is in you, whom you have received from God? You are not your own;
2 Corinthians-6:16
For you are the temple of the living God

However in Hebrews we have Assembly should not be forsaken.

Hebrews 10:25 (NKJV)
..not forsaking the assembling of ourselves together, as is the manner of some, but exhorting one another, and so much the more as you see the Day approaching.

If our body is the Church, What is the place when we gather on the Sabbath day, as we call it too as Church? Is that just an assembly? Is that just enough to keep our body Holy and ignore the gathering? If God lives in the Church, our Body, Is the congregation is needed?
Our bodies are not the church.

The verse in 2 Corinthians that you quote says that our bodies are temples. In context this is saying that we (rather than a building) are the dwelling place of the Holy Spirit. In the OT his presence would rest in the temple and that was considered his dwelling among his chosen people. In the NT this took a new form -- the vail in the temple was torn asunder -- and his spirit actually lives within those who have been called according to his purpose.

It is only together in fellowship that we make up the church. Believers collectively are a body: the church.