A paragraph break is appropriate here, as in Revised Standard Version.

Since wars often occurred in the country, Simon the son of Mattathias, a priest of the sons of Joarib, and his brothers, exposed themselves to danger and resisted the enemies of their nation: Since wars often occurred in the country may be expressed as “Our enemies often attacked Judea.” A priest of the sons of Joarib is literally “the son of the sons of Joarib” (so Kappler’s Greek text). Similar to Revised Standard Version, Good News Bible reads “a priest of the Jehoiarib family.” This is a textual matter. Our recommendation is that the word “priest” not be brought in here. For the spelling of Joarib, see the comments on 1Macc 2.1. Simon the son of Mattathias, a priest of the sons of Joarib, and his brothers may be rendered “Simon and his brothers, the sons of Mattathias from the Joarib family.” Exposed themselves to danger is well translated in Good News Bible and Contemporary English Version as “risked their lives.” Good News Bible renders their nation as “our nation” since it is the nation of the speakers also, not just the Maccabees. Other languages may find this adjustment helpful. An alternative model for the first half of this verse is “Our enemies often attacked Judea. So Simon and his brothers, the sons of Mattathias from the Joarib family, risked their lives and fought back whenever these enemies attacked.”

In order that their sanctuary and the law might be preserved: Instead of the pronoun their, Good News Bible uses “our” again. Their sanctuary refers to the Temple (see 1Macc 1.21). The law is the Law of Moses.

And they brought great glory to their nation may be rendered “and they made us famous” or “and they brought great honor [or, face] to our nation.”

An alternative model for this verse is:

• “At one time there were frequent wars in our country [or, Our enemies often attacked Judea]. So Simon and his brothers, the sons of Mattathias of the Joarib family, risked their lives in fighting these enemies. They did this to preserve their [or, our] Law [or, the Law of Moses] and their [or, our] Temple, and they have made their [or, our] country a proud and respected nation [or, they have brought great honor to our nation].

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Maccabees. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here.