How do you reconcile Hillel (1) and Rabi Akiva (2) with the Mishnah Torah (3) and Shulchan Aruch (4)?
"What is hateful unto you, do not do unto your neighbor. That is the whole Torah, all the rest is commentary. Now go and study." - Hillel
"And you should love your fellow as yourself; this is a great principle in the Torah." - Rabi Akiva
"One who does not acknowledge the validity of the Oral Law... should be put to death by any person.... Like all the rest of the heretics who say that the Torah is not Divine in origin.... There is no need for witnesses, a warning, or judges for them to be executed. Instead, whoever kills them performs a great mitzvah." - Rambam (Mamrim 3)
"The apikorsim, and those who do not believe in the Torah and in the Jewish prophecy, it is a mitzvah to kill them. If one has strength in his hand to kill them with a sword, in public, he should kill him." - Shulchan Aruch (Yoreh Deah 158:2)