36 He also told them a parable: “No one tears a piece from a new garment and puts it on an old garment. If he does, he will tear the new, and the piece from the new will not match the old. 37 And no one puts new wine into old wineskins. If he does, the new wine will burst the skins and it will be spilled, and the skins will be destroyed. 38 But new wine must be put into fresh wineskins. 39 And no one after drinking old wine desires new, for he says, ‘The old is good.’ “

Luke 5:36-39

Old Covenant and New Covenant 

The “old” things that Jesus is talking about with such descriptive analogies represent what we often call the old covenant, and the “new” things represent the new covenant. Jesus is the fulfillment of the old. The old foreshadowed the Messiah, longed for Him, and endured all manner of hardships en route to His presence. Jesus is the substance that the old covenant was representing. Jesus is the truest High priest. Jesus is the truest prophet. Jesus is the truest King. Jesus is the truest sacrificial lamb. Jesus is the truest Temple. Jesus is the truest mediator. 

Not only is Jesus the fulfillment of the old covenant, but He is the establisher of the new covenant. That new covenant was promised in the old but could not be realized without Jesus. Jeremiah, for example, wrote, “Behold, the days are coming, declares the Lord, when I will make a new covenant with the house of Israel and the house of Judah, not like the covenant that I made with their fathers on the day when I took them by the hand to bring them out of the land of Egypt, my covenant that they broke, though I was their husband, declares the Lord. For this is the covenant that I will make with the house of Israel after those days, declares the Lord: I will put my law within them, and I will write it on their hearts. And I will be their God, and they shall be my people. And no longer shall each one teach his neighbor and each his brother, saying, ‘Know the Lord,’ for they shall all know me, from the least of them to the greatest, declares the Lord. For I will forgive their iniquity, and I will remember their sin no more. (emphasis is mine)” 

To better follow Jeremiah’s prophecy, we ought to have a working knowledge of the old and new covenants. The old covenant is the covenant that God made with Israel after the Exodus. Moses was the mediator of that covenant between Israel and God, and the promises of that covenant were essentially conditioned upon obedience. If Israel would obey God’s laws, then they would have God’s blessings. Jeremiah is prophetically speaking about a new covenant that will not be conditioned upon human obedience. That new covenant will be different based on God’s future action to cause each individual of that new covenant to know God intimately. God will forgive Their sins, not because they obeyed the right conditions but through free grace. 

The Law and the Gospel.

Using these terms in a generally wide sense, we may describe the old covenant by the term “law” and the new covenant by the term “gospel.” Theodore Beza famously wrote, “we divide this word (The Bible) into two principal parts or kinds: the one is called the “Law,” the other the ‘Gospel.’ For, all the rest can be gathered under the one or the other of these two headings.” What is Beza trying to teach us? The Scriptures’ entire teaching can be categorized under two headings of ‘law’ or ‘gospel.’ The category of ‘law’ demands us to perform our own righteousness. However, the category of ‘gospel’ announces that Jesus performed righteousness for us and offers it to us by grace through faith. Even simpler put, the law says to me, “Aaron, you must do,” but the gospel says to me, “Aaron Jesus has already done.” 

Don’t Mix Up the Old and New.

Jesus’s warning was to all who might attempt to mingle the law and the gospel. He was warning us to avoid combining the old and new covenants to create a third thing. The old covenant was good. The new covenant is better. He warns, if you try to put new wine into old wineskins, the wineskins will burst, and you will waste all the goodness. In his letter to the Galatians, the Apostle Paul will combat the error of adding to Christian worship and assurance. In other words, he’s rehearsing the distinction that Jesus made about not putting new wine in old wineskins. The promises of the gospel are given by grace alone and not grace mixed with merit. The promises of the gospel are grasped by faith alone and not faith and works. The promise of the gospel is available in Christ alone and not Christ and law-keeping. The gospel is better. 

So What?

Christian, this parable of Jesus reminds us to avoid thinking that the good news of our acceptance with God in Christ hinges upon our personal obedience. The law of God is good and demands us to obey. The fundamental problem we have with the law is ourselves. We are unable to obey God’s law perfectly, and therefore we are condemned by it. The law of God promises us the reward of eternal life through merit. The law is good, but I am not, and that is our common predicament. The gospel, on the other hand, is an announcement to be celebrated. The law terrifies sinners because it demands obedience with a promise of either life or death. The reward for law-keeping is life. The reward for law-breaking is death. This sobering reality is where Jesus enters into the story at the perfect time (Gal 4:4), and He merited eternal life through obeying the law of God. This Gospel thrills the sinner because those demands of obedience have been fulfilled, and life is now offered freely to all who believe. 

Would anyone really try to mix the gospel and the law? Are there people today who put the new substance of the gospel into the law’s old containers? Sadly, yes. The problem is felt by many who are believing in Jesus as their Saviour but constantly struggle with peace and assurance because they are not worthy. Christian, you don’t feel worthy of Jesus because you are not worthy of Jesus, and He has set His love upon you because of His character and not yours. Fret not. Let the gracious gift of divine acceptance permeate your heart. As the gospel takes root deeper and deeper into your soul, your outward living will naturally produce the fruit of that Holy Spirit planted tree.