Once the potter finishes working with a piece of clay on the wheel, it gets sent to kiln to be hardened with heat. The potter's wheel is only the first stage of the pottery process. The potter may have shaped a lump of clay into a beautiful bowl, plate, vase, or whatever he desired, but it is not yet ready to be placed into service. For the purpose of this article, I will use a water pitcher as an example. The pitcher may have a beautiful shape, but it is still damp clay that will lose its shape if any liquid is placed into it. It can also be easily deformed by even a slight amount of pressure. It must now be placed into a kiln to go through a process that potters call “firing.” It is because the process uses tremendous heat that it is known today as “firing.” the pottery.

At the time the Old Testament was being written, the Israelites used a type of kiln referred to today as a “beehive” kiln. It was used throughout the Egyptian and Persian empires and was in use right through the Iron Age. The kiln is a type of oven that produces temperatures hot enough to harden objects made from clay into pottery. The kilns could produce temperatures between 800-1000 degrees Celsius. This amount of heat is needed to permanently alter the chemical makeup of the clay so that it takes a permanent shape. This super-heated shape can then only be altered by breaking the finished product.

The final look of a piece of fired pottery is dependent on the molding that the potter applied to the clay before placing it into kiln. In other words, clay that is shaped like a water pitcher will retain that shape because it has been hardened by the heat. It cannot be reshaped after it comes out of the kiln. The pottery is also affected by any glazes that are applied to it for decoration, and also by the temperature within the kiln. The finished look of the pottery depends on the type of clay that is used, the application of any glazes, and the heat within the kiln.

When a piece of clay is on the potter's wheel, it is wet and very pliable, containing a great deal of water. The clay particles ride within the water, which is what makes clay plastic, or easily workable. The potter keeps the clay very wet while it is spinning on the wheel. This water, however, needs to be removed. After the clay pottery has been placed inside the kiln, the fire is lit and the kiln slowly begins to heat. As the heat slowly rises to 100°C, any moisture that is inside the clay is drawn out and evaporated. This is a critical stage for the clay: if the temperature rises too quickly the water will boil and cause the clay to explode.

As the temperature rises between 480-700°C, the clay begins to gradually vitrify. Vitrification is the process of melting that clay goes through as it is fired to maturity. In a fully matured clay body, the spaces between refractory particles (material that resists melting) are completely filled up with glass, fusing the particles together and making the clay pottery impervious to water. This process of melting and fusing also compresses the clay body, causing it to shrink a little bit. The clay shrinks slightly as the particle sizes slowly decrease as they fuse. As this happens, the particles also compress into a dense configuration within the glassy material that fills up all the nooks and crannies. In other words, the pottery comes out stronger than it went in.

Clay comes from the earth and therefore contains some measure of carbon, organic materials, and sulfur. All of these elements burn off between 300° and 800°C. These elements need to be removed or else defects will occur in the pottery during vitrification. If they get trapped inside the clay instead being released, the clay will become discolored and the pottery shape may become distorted.

Another thing that happens at this temperature is that chemical water (referred to as “water smoke”) is driven off. What is chemical water? The chemical composition of clay is one molecule of alumina and two molecules of silica bonded with two molecules of water. This chemically combined water's bond loosens when heated. The overlapping the carbon and sulfur molecules burn off and the chemically bonded water escapes from the clay. If this water inside the clay heats too quickly, it again can cause the explosive production of steam inside the clay resulting in a destroyed piece of pottery. Temperature control is extremely important.

At about 900°C the clay particles begin to fuse with each other. This bonding process is called sintering in the pottery world. After the clay has bonded, or sintered, it is no longer truly clay but has instead become something that is called ceramic material. At this point the ceramic material can be cooled, removed from the kiln, and painted with glazes for decoration.

The glaze painted ceramic pottery is then placed back into the kiln to finish the firing process. The kiln is then heated to about 1000°C. At this temperature, the ceramic material matures and the glazes are sealed into the material. When it is removed from the kiln, what was once a wet piece of clay shaped on the potter's wheel is now a beautiful piece of pottery.

Now that I've given a brief lesson in ancient kilns, let me correlate this over to your spiritual life. The period of time you spent on God's potters wheel may have been an uneasy time for you. Having your life molded into the shape that God sees fit is never easy. You're about to be placed into the kiln of life where God is going to finish the process he started. The Apostle Paul wrote in Philippians 1;6 “I am sure of this, that He who started a good work in you will carry it on to completion until the day of Christ Jesus.” The process of being “fired” in the kiln is what God uses to bring us to spiritual maturity.

When we accept Jesus as our personal Lord and Savior, we are forgiven of our sins. We still have the problem of sin-like behavior such as envy, jealousy, anger, lying, rebellion, bitterness, unforgiveness (to name a few), that still needs to be purged from our lives. Some versions of the Bible call this “carnality” and other versions call it “flesh.” For the average Christian, this removal process happens over time as God works in our lives slowly transforming us into his image. This “water” in us needs to be removed, so God places us in the kiln and slowly turns up the heat.

Each person’s kiln is different. God knows that you are different from everyone else on the planet and he knows exactly how to remove your “water.” Sometimes God turns up the heat by sending us into a trial, or situation of some sort. Perhaps you get a supervisor who despises you, or perhaps you lose your job, or any situation that is drastic to you. You may be praying for this situation to change and it isn't changing: it's just getting worse. I would like to suggest that you may be in the kiln and God may be turning up the heat. This is the time to seek God and find out what he's doing. If you're in the kiln, then God is in the process of removing something from your life that he doesn't want in it. Don't look at the situation as negative thing; look at it as a positive thing. Romans 12:12 (Contemporary English Version) says: “Let your hope make you glad. Be patient in time of trouble and never stop praying.” The Potter is in control of the heat and he knows exactly how much you need. He wants to evaporate those negative qualities out of your life and you need to let him do it.

We have an idiom in the United States that says: out of the frying pan and into the fire. This simply means that you may get out of one problem, only to immediately find yourself in a worse situation. However, you may actually still be in the kiln going through God's vitrification process. In this process, the heat is increased even more to take you to next level. In pottery this process burns off carbon, organic materials, and sulfur that cause discoloration and surface defects. In your life, this process burns off bad habits and “secret” sins that prevent your witness from being effective. If everything in your life seems to be going from bad to worse, please consider that you may be going through the vitrification process in God's kiln of life. Once again, the Potter is in control of the heat and this process requires a lot of heat to burn off these impurities.

We often look at the problems of life that we are going through and blame the devil for what is happening. In reality, the devil may have nothing to do with the situation. We forget, or don't even realize that we are in God's kiln and He is completely in control. Tremendous heat is tremendously uncomfortable. Tremendous heat however, is a prerequisite to burn off the impurities in our life. The trials we go through in life are nothing more than the heat God uses in the kiln of life. Our goal should not be to get out of the trials, to get out of the heat, or to get out of the kiln; our goal should be to let God remove the impurities from our lives. Our goal should be to become more Christ-like. Let us not abhor our time in the kiln but embrace our God who created this kiln.

So what do you do if you realize that you are in God’s kiln going through the firing process?

• Confess any sin in your life to God. As a side note, for the Christian, unconfessed sin does not affect your standing with God, you are still saved and still going to heaven. Unconfessed sin does, however, affect your effectiveness for Christ. For the purpose of this article, I am assuming that you are already saved. Unconfessed sin can stop prayers from being answered (Psalm 66:18), and can cause us to lose our peace and joy (Romans 14:17). We even read in Psalm 38 that David became ill due to unconfessed sin. The point is this; if there is any unconfessed sin in your life, get on your knees and confess it to God.
• Search your heart and your life for any “carnal” or “fleshly minded” behavior. Here are some examples from Galatians 5:19-21; sexual immorality, impurity, sensuality, idolatry, sorcery, enmities, strife, jealousy, outbursts of anger, disputes, dissensions, factions, envying, drunkenness, carousing, and things like these. If you see one or more of these in your life, God may have you in the kiln to burn them out. If any of these are in your life, confess it to God and believe that He will remove it.
• Be positive even while you are going through this, or any, trial in God's kiln. James 1:2-4 says (Holman Standard Christian Bible HSCB) “Consider it a great joy, my brothers, whenever you experience various trials, knowing that the testing of your faith produces endurance. But endurance must do its complete work, so that you may be mature and complete, lacking nothing.” The question to ask is, “Do I have the right attitude as I am being fired in the kiln of life?” Remember that you can be positive and joyful, but you can also be rude, crude and obnoxious as well. What is your attitude toward life? What is your character when everything is falling apart due to the heat of the kiln? Our goal is to be positive in the heat.
• The goal of being placed into the kiln is to come out as a spiritually mature person. A spiritually mature person is sensitive to the needs of those who are around them. A spiritually mature person doesn't just look out for their own needs (which is easy to do when you're in the kiln) - they are also aware of the needs of others. We understand that there are many others around us that are hurting and have needs as well. They may be in the kiln just like you are. Comfort them and let them know that God is in control and that they will come out of the kiln as a beautiful piece of pottery.

Remember that your time in the kiln is limited. You will not be in there forever, though it may feel like it. When God takes you out of the kiln you will be ready for service. Just as pottery has to go through a maturation process, so you also go through a spiritual maturation process. You enter the process as wet piece of shaped clay, and come out as a beautiful piece of pottery. Let the trials come. Let the heat be turned up. Let the imperfections be burned out of you. God is in control and end product is worth the effort. God will not put you into a fiery trial that you cannot handle just as a potter does not put more heat in the kiln than the clay can handle. God knows exactly how much trial, or pressure, or heat that you need to transform you into a spiritually mature Christian. Though it may not be easy, trust your life to the Potter and He will transform you from clay to pottery.