By Hannah's Cupboard, A ministry of Barbara Ladinais
Those four mysterious Creatures in Ezekiel signify the four greater divisions of animate creation. All of creation is represented giving God the adoration he deserves.
The fact that the creatures are full of eyes symbolizes God's all-seeing nature and the omnipresence of God. The numerous eyes may be a sense of constant watchfulness.
The wheels touched the earth and could move in any direction probably indicates God's rule and control over the affairs of the earth.
We can join all of heaven in proclaiming His greatness, who was and who is and who is to come.
Picture posted by James Donovan - prophetic art
What did the four living creatures in Ezekiel signify? How come they each had a face representing the ox, eagle, lion and man? What's up with the wheel in the middle of a wheel?
Mysterious Creatures 
The four living creatures are beings created by God who reside around his throne. When Ezekiel saw them he was glimpsing into the third heaven and seeing what takes place in heavenly eternal places (Ezekiel 1). He is not the only one who saw them.
John the Apostle also saw "around the throne, four living creatures full of eyes in front and behind." Here is what they continuously proclaim: "'Holy, Holy, Holy, is the Lord God, The Almighty, who was and who is and who is to come.'" (Revelation 4:8)
Picture taken from Explore Eagle Ezekiel, Ezekiel 10, and more! (Pinterest)
Can you imagine trying to describe something that has no equal on earth and that you have never seen or suspected existed before? Both Ezekiel and John gave it their best shot but human language falls far short of describing "things which eye has not seen and ear has not heard, and which have not entered the heart of man." (1 Corinthians 2:9)
Because these creatures reside in heaven, there is much mystery surrounding them and their meaning. We are not privy to understand their total significance so we also have to give it our best shot and know that we simply don't yet know all the answers.
What did the four living creatures in Ezekiel signify?
What do the living creatures signify? Generally it is believed they represent the four greater divisions of animate creation: wild beasts for the lion; domesticated beasts for the calf; humanity for the man and birds/flying creatures for the eagle. Because they proclaim praise, worship and thanksgiving; all of creation is represented giving God the adoration he deserves.
"Their legs were straight; their feet were like those of a calf and gleamed like burnished bronze." (Ezekiel 1:7).
"Their faces looked like this: Each of the four had the face of a human being, and on the right side each had the face of a lion, and on the left the face of an ox; each also had the face of an eagle." (Ezekiel 1:10).
"They each had two wings spreading out upward, each wing touching that of the creature on either side; and each had two other wings covering its body." (Ezekiel 1:11).
How come they each had a face representing the ox, eagle, lion and man?
Some see the various faces symbolizing God's rule over all of creation. The fact that the creatures are full of eyes symbolizes God's all-seeing nature and the omnipresence of God. Another aspect of the numerous eyes may be a sense of constant watchfulness.
Picture posted by Dolores Develde, FineArtAmerica.com on 30 May 2015 - The Throne Room Of God
What's up with the wheel in the middle of a wheel?
The wheel inside the wheel? The fact that one of the wheels touched the earth and could move in any direction probably indicates God's rule and control over the affairs of the earth. He can go where he wants whenever he wants. The wheels followed the spirit which may represent the Holy Spirit.
Artwork by Larsen - The Wheels
Picture posted by The Watchman's Post on 10 July 2016
From Wikipedia, the free encyclopedia
When we lift up praise to the King of Kings we can add our praise to theirs. We can say: "I join all of heaven in proclaiming your greatness O Mighty God." In that we are as close to the four living creatures as a prayer's breath away.
Picture posted by Arte Digital
 Women Journeying Through The Bible . . ., Posted on 31 March 2015, Week 5 - Expecting . . . WAKE UP!, http://wjttb-womenofthebible.weebly.com/blog/week-5-expecting
 Daniel E. Woodhead, posted on 10 September 2015, The Heavens Opened to The Prophet Ezekiel, http://doctorwoodhead.com/the-heavens-opened-to-the-prophet-ezekiel/
New International Version (NIV), Holy Bible, New International Version®, NIV® Copyright ©1973, 1978, 1984, 2011 by Biblica, Inc.® Used by permission. All rights reserved worldwide.
1 Corinthians 2:9 - https://www.biblegateway.com/passage/?search=1+Corinthians+2%3A9&version=NIV
Ezekiel 1 - https://www.biblegateway.com/passage/?search=Ezekiel+1&version=NIV
Ezekiel 1:10 - https://www.biblegateway.com/passage/?search=Ezekiel+1%3A10&version=NIV
Ezekiel 1:11 - https://www.biblegateway.com/passage/?search=Ezekiel+1%3A11&version=NIV
Revelation 4:8 - https://www.biblegateway.com/passage/?search=Revelation+4%3A8&version=NIV