These are some of the ones that always stuck with me in Catholic school:
Deuteronomy 13:6-17New International Version (NIV)
6 If your very own brother, or your son or daughter, or the wife you love, or your closest friend secretly entices you, saying, "Let us go and worship other gods" (gods that neither you nor your ancestors have known, 7 gods of the peoples around you, whether near or far, from one end of the land to the other), 8 do not yield to them or listen to them. Show them no pity. Do not spare them or shield them. 9 You must certainly put them to death. Your hand must be the first in putting them to death, and then the hands of all the people. 10 Stone them to death, because they tried to turn you away from the Lord your God, who brought you out of Egypt, out of the land of slavery.11 Then all Israel will hear and be afraid, and no one among you will do such an evil thing again.
12 If you hear it said about one of the towns the Lord your God is giving you to live in 13 that troublemakers have arisen among you and have led the people of their town astray, saying, "Let us go and worship other gods" (gods you have not known), 14 then you must inquire, probe and investigate it thoroughly. And if it is true and it has been proved that this detestable thing has been done among you, 15 you must certainly put to the sword all who live in that town. You must destroy it completely,[b] are to be found in your hands. Then the Lordwill turn from his fierce anger, will show you mercy, and will have compassionon you. He will increase your numbers, as he promised on oath to your ancestors
Deuteronomy 20:10-18New International Version (NIV)
10 When you march up to attack a city, make its people an offer of peace. 11 If they accept and open their gates, all the people in it shall be subject to forced labor and shall work for you. 12 If they refuse to make peace and they engage you in battle, lay siege to that city. 13 When the Lord your God delivers it into your hand, put to the sword all the men in it. 14 As for the women, the children, the livestock and everything else in the city, you may take these as plunder for yourselves. And you may use the plunder the Lord your God gives you from your enemies. 15 This is how you are to treat all the cities that are at a distancefrom you and do not belong to the nations nearby.
16 However, in the cities of the nations the Lord your God is giving you as an inheritance, do not leave alive anything that breathes. 17 Completely destroy[a]them-the Hittites, Amorites, Canaanites, Perizzites, Hivites and Jebusites-as the Lord your God has commanded you. 18 Otherwise, they will teach you to follow all the detestable things they do in worshiping their gods, and you will sin against the Lord your God.
Deuteronomy 13:6-17New International Version (NIV)
6 If your very own brother, or your son or daughter, or the wife you love, or your closest friend secretly entices you, saying, "Let us go and worship other gods" (gods that neither you nor your ancestors have known, 7 gods of the peoples around you, whether near or far, from one end of the land to the other), 8 do not yield to them or listen to them. Show them no pity. Do not spare them or shield them. 9 You must certainly put them to death. Your hand must be the first in putting them to death, and then the hands of all the people. 10 Stone them to death, because they tried to turn you away from the Lord your God, who brought you out of Egypt, out of the land of slavery.11 Then all Israel will hear and be afraid, and no one among you will do such an evil thing again.
12 If you hear it said about one of the towns the Lord your God is giving you to live in 13 that troublemakers have arisen among you and have led the people of their town astray, saying, "Let us go and worship other gods" (gods you have not known), 14 then you must inquire, probe and investigate it thoroughly. And if it is true and it has been proved that this detestable thing has been done among you, 15 you must certainly put to the sword all who live in that town. You must destroy it completely,[b] are to be found in your hands. Then the Lordwill turn from his fierce anger, will show you mercy, and will have compassionon you. He will increase your numbers, as he promised on oath to your ancestors
Deuteronomy 20:10-18New International Version (NIV)
10 When you march up to attack a city, make its people an offer of peace. 11 If they accept and open their gates, all the people in it shall be subject to forced labor and shall work for you. 12 If they refuse to make peace and they engage you in battle, lay siege to that city. 13 When the Lord your God delivers it into your hand, put to the sword all the men in it. 14 As for the women, the children, the livestock and everything else in the city, you may take these as plunder for yourselves. And you may use the plunder the Lord your God gives you from your enemies. 15 This is how you are to treat all the cities that are at a distancefrom you and do not belong to the nations nearby.
16 However, in the cities of the nations the Lord your God is giving you as an inheritance, do not leave alive anything that breathes. 17 Completely destroy[a]them-the Hittites, Amorites, Canaanites, Perizzites, Hivites and Jebusites-as the Lord your God has commanded you. 18 Otherwise, they will teach you to follow all the detestable things they do in worshiping their gods, and you will sin against the Lord your God.