He must increase, but I must decrease

Numbers 29:12-16 (ESV)
"On the fifteenth day of the seventh month you shall have a holy convocation. You shall not do any ordinary work, and you shall keep a feast to the LORD seven days. [13] And you shall offer a burnt offering, a food offering, with a pleasing aroma to the LORD, thirteen bulls from the herd, two rams, fourteen male lambs a year old; they shall be without blemish; [14] and their grain offering of fine flour mixed with oil, three tenths of an ephah for each of the thirteen bulls, two tenths for each of the two rams, [15] and a tenth for each of the fourteen lambs; [16] also one male goat for a sin offering, besides the regular burnt offering, its grain offering and its drink offering.

The fifteenth day of the seventh month was the feast of booths, in which Israel were to spend seven days in booths to remember their time in the wilderness when God brought them out from Egypt. Why were they to keep this feast? That when they enter into the promised land, they would remember that they were sojourners, with no permanent home on that other side of the Jordan.

Likewise, we Christians also have no lasting city on this earth. We are sojourners here, and we dwell in temporary booths of our body, which is ready to waste away. Our home the New Jersusalem is where our hearts belong, for there we have stored eternal treasures. It is where our Treasure, Christ, is. Jesus Christ has gone before us to prepare a place for us in His Father's house, in which are many rooms. In heaven, the hardship and suffering that we went through on earth will be considered a cause for celebration. We will rejoice there, knowing how much we have compared to when we were pilgrims on earth. Surely we are most miserable of all if only on this world we have hope. But God has promised for us a kingdom which we will inherit, and hope of resurrection in a glorious body.

The purpose of this feast was then that Israel would rejoice in the Lord:
Leviticus 23:40 (ESV)
And you shall take on the first day the fruit of splendid trees, branches of palm trees and boughs of leafy trees and willows of the brook, and you shall rejoice before the LORD your God seven days.
While feast of trumpets and the day of atonement were solemn assemblies where Israel were to think of the seriousness of their sins and the greatness of God's mercy, the feast of booths was a feast to celebrate and to rejoice before God who had saved them. Likewise we do well to not only be grave and mournful over our sins and our Saviour's sacrifice, but also to rejoice before our God for what He has done for us. Through this feast, God is teaching us rejoicing is what we will be doing in heaven. We will keep the feast there, with palm trees in our hands:
Revelation 7:9-10 (ESV)
After this I looked, and behold, a great multitude that no one could number, from every nation, from all tribes and peoples and languages, standing before the throne and before the Lamb, clothed in white robes, with palm branches in their hands, [10] and crying out with a loud voice, "Salvation belongs to our God who sits on the throne, and to the Lamb!"

Thirteen bulls from the herd. On the first day of this feast Israel was commanded to offer thirteen bulls, then on the second day twelve, and on the third day eleven and so on, until on the seventh day seven bulls were required. What does this decrease in the number of offering suggest?
Perhaps it signifies the sanctification process of the saint. This interpretation is fitting, as the feast was about Israel's time in the wilderness, in which Israel was tested and sanctified.
Likewise, when we were saved and began this journey in the wilderness with Jesus, at first there were great battles with sin. Israel also, how much did they rebel and sin before God when they first began their journey, even from the moment they set foot out from the ground of the Red Sea! But slowly, as we learn to discern good and evil and learn the fear and the grace of the Lord, and as we learn how to walk in the Spirit and how to die with Christ and how to hear the voice of our Shepherd, we sin less and less, and become holier and holier. There is less covering of sin needed. Sure, the saint as he grows realizes increasingly how depraved and dead he is apart from Christ, but his faith in Christ grows. It is like Abraham, whose body became more dead as the years went pass, and more he hated his and his Sarah's bodies for their inability to make a seed, but his faith in God who can do impossible things grew more and more, giving glory by faith unto Him. It is so with the Christian. As we realize the greatness of God's love and grace over us, we don't sin more, as wicked men would presume, but we become less sinful. We see that it is all by grace, and without his grace we would have never even breathed. We realize what wicked sins have we repaid our master, who loved us so much. We so begin to sin less, not in order to be saved, but because we realize we have been saved and are debtors. We more willingly give ourselves to Him, and increasingly it becomes not a grudge to walk with Him. And we give up more and more of ourselves and our sins. Our old man dies more and more, losing his strength everyday on the cross. It comes to pass as it was said by John the Baptist:
John 3:30 (ESV)
He must increase, but I must decrease.
As the road becomes narrower and narrower, we have to give up the loads that we have carried with us, that at last, we will have nothing left for us but Jesus Christ. As it is written:
Numbers 29:35-36 (ESV)
"On the eighth day you shall have a solemn assembly. You shall not do any ordinary work, [36] but you shall offer a burnt offering, a food offering, with a pleasing aroma to the LORD: one bull, one ram, seven male lambs a year old without blemish,

On the last day Israel was to offer only one bull. In the end of our lives for us also, we only have one thing left, Jesus Christ's grace for us. Our bodies shall waste away, and our possessions will mean nothing, and we will be ready to part with our family. There will only be left the love of God which is Jesus Christ, which even death cannot separate. There will be nothing left but the word of God that has been sown in our hearts. There will be no other business on our deathbed, but pleasing the Lord. There will be no thought of this world, but only of eternity and the hope of the resurrection. How glorious shall we be when we enter in, trusting only in the name of Jesus Christ, the Lamb of God. All who trust in their own righteousness and other gods shall be ashamed, as they find themselves in Hell. That God would rescue people who do not know Jesus Christ that are in the earth! There is no hope outside Christ. That men would know that ALL that matters at the last Day will be whether we have Jesus or not!

Let us decrease every day, and let Christ increase in us every day. All human beings are same on their deathbed. All human beings may not have many things in common, but one thing we all share, the wretchedness of our death because of our sins. Let us remember that Jesus Christ is all that matters. Let us die with Him now, crucified with Him, that we would not be ashamed on judgment day, realizing we have lived our lives for ourselves, and not for Him who died and rose again. Let us pray to God to sanctify us completely, working death in us, that we may partake in Christ's glorious life. Let us forsake every load that which is not Christ's yoke, that we can walk this narrow road to salvation. Let us endure suffering here as a good soldier of Christ, knowing that in heaven we will rejoice. Thank You Lord, for Your word:
Matthew 10:38-39 (ESV)
And whoever does not take his cross and follow me is not worthy of me. [39] Whoever finds his life will lose it, and whoever loses his life for my sake will find it.