Filters are important. Your car filters the oil, your AC in your home filters your air, and the city filters the water. All these efforts are done to purify the host to receive needed elements. Most things need filters in our polluted world. Our body is no different. God gave humans kidneys as filters to segregate out waste and keep our bodies with only the necessary nutrients.
God designed the kidneys to work in this way, but they do not always work correctly. If someone has kidney damage, what happens is that their kidneys begin to die. Basically, our kidneys are like a sponge, soft and able to filter out lots of unneeded stuff. When kidneys die, however, they begin to harden. The difference between a healthy kidney and a dead one is the difference between a new sponge and a rock. If water is poured over a sponge and a rock, only the sponge would soak up anything. In the same way, only a healthy kidney soaks up unnecessary waste. If someone’s kidneys get bad enough, it becomes necessary to do a kidney transplant to remove the rock of a kidney they have and replace it with a soft spongey organ.
I was thinking of this example today as I meditated on God’s promises to His people in the New Covenant. The New Covenant was promised by God to His people in the Old Testament, but was not inaugurated with His people until the New Testament (remember Jesus saying to His disciples at the last supper that His blood was the blood of the New Covenant?) In the New Covenant, God establishes a new agreement for how He intends to relate to His people. In the Old Covenant, the sins of the people were dealt with temporarily by offering up animal sacrifices and approaching God through key leaders known as priests. In the New Covenant, the sins of the people are dealt with permanently through Jesus sacrificial death on the cross and all people are invited to approach God directly through the invitation of our High Priest Jesus Christ.
In order to establish this kind of a relationship, however, God needed to give His people a heart transplant. Ezekiel 36:25-27 says this of the New Covenant, “I (God) will sprinkle clean water on you, and you shall be clean from all your uncleannesses, and from all your idols I will cleanse you. And I will give you a new heart, and a new spirit I will put within you. And I will remove the heart of stone from your flesh and give you a heart of flesh. And I will put my Spirit within you, and cause you to walk in My statutes and be careful to obey My rules.” God looks at the situation of humanity, and realizes that without Christ, we are spiritually dead. Therefore, He needs to cleanse us, but then He needs to give us a new heart that will receive the essential element of His Spirit that He wants to give. This is the idea spoken of in 2 Corinthians 5:17, “If anyone is in Christ, he is a new creation. The old has passed away; behold the new has come.” In the New Covenant, all who trust in Jesus Christ for the forgiveness of their sins are not only forgiven, but they are given a new life, with a new heart that receives the Holy Spirit of God that empowers them to live the life God is calling them to live.
This Christmas, you will no doubt see countless pictures and figurines of babies in mangers. Babies are an easy symbol of new life. As you see the infant Jesus this Christmas, let it remind you that His “new life” in Bethlehem brings new life to all who believe in Him. Praise God for this indescribable gift!