In Deuteronomy 27 the Lord commanded the Israelites to set up an altar at Mount Ebal after they arrived in the promised land. The words of the law were to be written on plaster covering the altar stones and the people were to making offerings there, eating and rejoicing together. In today's passage Joshua fulfills this commandment.
"Then Joshua built on Mount Ebal an altar to the Lord, the God of Israel, as Moses the servant of the Lord had commanded the Israelites. He built it according to what is written in the Book of the Law of Moses---an altar of uncut stones, on which no iron tool had been used. On it they offered to the Lord burnt offerings and sacrificed fellowship offerings." (Joshua 8:30-31) Moses had said no tools must be used on the stones---the stones were to be used just as the Lord made them, with no attempts by man to "improve" upon their shape. When we studied Deuteronomy we talked about how we must approach and worship the Lord in His way. He offered the First Covenant and set the terms of it; there was nothing man could do to improve upon it. Man's duty was to obey it exactly as it was written. The Lord also offered the New Covenant and set the terms of it; there is nothing we can do to improve upon what God the Son has already done for us. Our duty is to believe on Him and trust that what He did for us saves us to the uttermost.
Just as he was told, Joshua writes the words of the covenant on the altar stones which he has covered with plaster as Moses instructed in Deuteronomy 27:4. "There, in the presence of the Israelites, Joshua wrote on stones a copy of the law of Moses." (Joshua 8:32) It is important to read the word of God over and over throughout our lives. The word of God is to be so much a part of our lives that even while we're doing other things we are to think about it and talk about it. "These commandments I give you today are to be on your hearts. Impress them on your children. Talk about them when you sit at home and when you walk along the road, when you lie down and when you get up. Tie them as symbols on your hands and bind them on your foreheads. Write them on the doorframes of your houses and on your gates." (Deuteronomy 6:6-9) In other words, wherever we go and whatever we do, our identity is that we are the children of God. Our primary duty is to honor and serve Him. If we read and meditate upon His word, it will sink down deep into our hearts and help us to make choices that bring glory to the name of our God.
"All the Israelites, with their elders, officials and judges, were standing on both sides of the ark of the covenant of the Lord, facing the Levitical priests who carried it. Both the foreigners living among them and the native-born were there. Half the people stood in front of Mount Gerizim and half of them in front of Mount Ebal, as Moses the servant of the Lord had formerly commanded when he gave instructions to bless the people of Israel." (Joshua 8:33) Moses said the tribes of Simeon, Levi, Judah, Issachar, Joseph and Benjamin were to stand at Mount Gerizim and that the tribes of Reuben, Gad, Asher, Zebulun, Dan and Naphtali were to stand at Mount Ebal. (Deuteronomy 27:12-13)
After the altar has been set up and the offerings made on it and the words of the law written on it, the law is read to the people. Moses had said that the blessings promised for keeping the law were to be read to the people and that the curses for breaking the law were to be read to the people. These things are done at this time. "Afterward, Joshua read all the words of the law---the blessings and the curses---just as it is written in the Book of the Law. There was not a word of all that Moses had commanded that Joshua did not read to the whole assembly of Israel, including the women and children, and the foreigners who lived among them." (Joshua 8:34-35) The details for this solemn assembly were described in Deuteronomy 27 and 28 if you'd like to go back and take another look at them. Those chapters contain the blessings and the curses, and as we noted when we studied Deuteronomy, the Lord spent more time discussing the curses than the blessings in order to imprint upon their minds how important it is to obey His holy word.
The Lord didn't promise the Israelites that life in the promised land would be perfect. Life in this fallen world isn't perfect for anyone. For proof of that we only have to take a look at the life of Jesus Christ. He lived a perfect, sinless life and kept every law of the Lord but still endured a great deal of hardship and pain on this earth. The Lord didn't promise the Israelites that if they stayed faithful to Him there would never be any difficult days. But He did promise them the power and peace of His presence. He did promise to protect their nation and cause it to prosper. He did promise to supply all their needs.
If you and I remain faithful to the Lord, we will still have difficult days on this earth because we are living on a planet polluted by sin and we live among people who don't love the Lord and who don't follow His precepts. But to the faithful the Lord shows Himself faithful. (Psalm 18:25, 2 Samuel 22:26) He will be with us on our good days and on our bad days. As the lyrics of one of my favorite worship songs go ("Graves Into Gardens" by Elevation Worship), "The God of the mountain is the God of the valley, and there's not a place Your mercy and grace won't find me again." Whether everything is going exactly as we want and we're shouting His praises from the mountaintop or whether we're having a tough time and feel like we're down in the valley, our God is with us. He will uphold us with His righteous right hand. (Isaiah 41:10) He will supply our needs. (Philippians 4:19) He will speak peace to our hearts. (Isaiah 26:3) As long as we live on this earth we will encounter trials and tribulations, but the One who has overcome the world is with us and is for us. (John 16:33) There is nothing we cannot overcome through Him.