On the basis of God's great acts for them (v. 14) Joshua appealed to the Israelites to commit themselves to Him anew. Though Israel was not guilty of idolatry at this stage in her history as she was later, this sin existed in the nation to some degree (cf. Lev. 17:7).
Joshua's offer to choose the God or gods they would serve (v. 15) was not, of course, an encouragement to consider the idols as an equally acceptable option. It was simply an oratorical device (i.e., polarization) to help the Israelites distinguish their choices and to make the right alternative more obvious. As a true leader Joshua announced his commitment and in so doing encouraged the people to follow his example.
"So we find throughout the entire book of Joshua an emphasis on choice--choice that makes a tremendous difference in history, for individuals, for groups, for future generations."213
The people responded by committing themselves to Yahweh (vv. 16-18). They would join Joshua in serving the Lord. Joshua did not want the people to make a superficial decision, however.
"The great need of most Christians is to learn that in themselves they simply cannotbe the people God wants them to be."214
Therefore Joshua reminded them of the difficulties involved in following the Lord (vv. 19-20). They would "not be able to serve the Lord"(v. 19) in their own strength simply by determining to do so (cf. Exod. 19:8). They had to remember that their God was holy and jealous (i.e., allowing no rival god in His peoples' affections). He would "not forgive your transgressions or your sins"(v. 19).
"When does God not spare (forgive)? (1) When transgression and sin is wilfully committed, and when (2) forgiveness would, as He foresees, lead to no amendment."215
The people confirmed their earlier decision (v. 21), and Joshua reminded them that they were witnesses against themselves in the renewal of this covenant (v. 22). They would condemn themselves by their own testimony if they forsook the Lord.
Joshua then repeated his command to put away all idols, physical and mental, and to turn their hearts to follow Yahweh exclusively (v. 23). Again the Israelites committed themselves to follow the Lord faithfully (v. 24).
