Judges 2

1 The angel of God, who had been with Israel from the time of the Exodus now addresses the people (Exo 14:19). Since the angel is using first person, it is obvious that the angel is a theophany of God.
2 The Israelites let the pagan people live and they did not destroy the pagan religious sights. Both were violations of God's commands.
3 This was a task that God had assigned the Israelites to, and He was not going to do it for them. When God assigns us tasks, the intention is that we work together at it. When we work together with anyone we tend to grow closer.

The unfortunate side effect is that the pagan people will constantly be a distraction to the people, both politically and spiritually. History will prove that the Israelites are enticed several times to worship pagan gods, and will suffer because of it.

4 It was discouraging for the people to know that God would no longer help them with this effort. Eccl 3 tells about the seasons of life, and the time for war had passed. They had not been completely successful, but they had done enough to settle the land and establish themselves as a permanent nation.
5 Bochim means "weepers."
10 God had commanded the Israelites over and over to teach their children the history of Israel and to worship Him regularly. Instead, the vast majority of Israelites became more concerned with their own lives than about God (Deu 6:10-12). The meanings of the memorials were either forgotten or relegated to the realm of legends. As time wears on, the significance of past events can be lost for those who did not experience it.
11 Far worse that indifference to God, they began to worship idols in opposition to Him.
12 The Israelites had not destroyed the pagan altars or practices in the land. Tolerance led to curiosity, which led to active participation. In our own lives and in our churches we must not tolerate sin or it will destroy us.
13 The pagan nations credited these two idols with control over weather, crops, animal fertility, and war. It is ironic that when the Israelites turned to these idols that these were the very things that failed.
14 God was angry at the Israelites because idol worship is treason against Him (Exo 20:4-6). For punishment, God turned the tables on the Israelites, just as He had promised (Deu 28:25-26). The pagan nations that the Israelites once conquered and enslaved now became the oppressors.
15 No matter what the Israelites tried they could not succeed because God was against them.
16 But God does not punish people just for the sake of punishment. He desires that punishment will encourage people to turn from evil and depend on Him. Given that the Israelites had largely forgotten about God and that His invisible nature can make "circumstantial" punishment ambiguous, He sent "judges" to the people. Judges, here, is meant to indicate a leader. These judges would work with God to save the Israelites from their plight and turn them back to God.
17 Despite God's mercy, the Israelites would vacillate between God and idols. It seems that the sinful nature in humans is so strong that it is easier to slip into evil than to stay committed to what is good.

In this and several other instances, idol worship is considered the spiritual equivalent to prostitution. Over and over God indicates that our relationship to Him is like that of a wife to her husband. If the wife becomes a prostitute then she violates the marriage. In a similar way, when people ascribe divine reverence to anything or anyone other than God, they violate the relationship that God created them for.

18 While a judge was living, he or she would exert a strong positive influence on the Israelites.
19 But when the judge died the Israelites would lose that influence and sink even further into sin.

One possible application is that we can not expect to live a godly life only by living up to someone else's standards. We must develop in our own characters the unchanging standards of God. Likewise, if we happen to be in a position of positive influence, we must find a way to help people develop godly character.

22 God was able to use the pagan people to "test" the Israelites. The Israelites' responses to the temptations offered by pagan practices would make it apparent whether they really loved God or not. Such testing is not meant to be oppressive or discouraging. If we succeed at one test we can more confidently pass other tests. If we fail a test, then we know what needs to be worked on. In many cases we may be tested again and again on the same subject, but we should not get frustrated at this. Those who love God will always seek to pass these tests. Those who ignore, deliberately fail, or give up on the tests prove they don't love God.
23 Verses 21 and 23 work together because the Israelites proved unfaithful even before Joshua died.