"if it seems" suggests choice, also Joshua confirms that a choice has been made Joshua 24:22 "you have chosen the Lord". The reason I ask this is because I think there are two sorts of choice:

1. God is always at anyone time for any person is either giving them the grace to obey His Law [e.g. 10 Commandments] or He is not giving them that grace. Any choice under these circumstances will be no more or less than an outworking of what God is doing in that situation. e.g. in Acts 17:26 God determines the times and places of the lives of people who are not seeking Him so that they should seek Him. Here human choices are determined by God; determined choice...
2. The other way of seeing choose/choice is to leave grace, God's part, out of our lives and say, "it is all up to us," "we are free"; free choice...

I have read many comments by Christians where they have equated "choice" with "free choice". However if God chooses our nurture and nature, [inc' grace], not us, and we make our decisions based on who we are then our choices are determined and not free.

Free choice is an old discussion point but to assume "choice" is "free choice" without realising that there might be another way to look at this word is to have no choice in our understanding. "choose for yourselves" is in contrast to, "as for me and my house". Joshua is not going to choose for them.

Choice has two aspects A. what it is based on. B. the effect it will have going on into the future. 

"choose for yourselves" emphasises that it is not going to be imposed by Joshua but it does not mean that the people making this choice are magically free from who they are...Who they are depends upon how they were made. How they were made depends upon God who made them. Therefore their choice will have been determined by God who made them... Can, or cannot, "choose" mean "determined choosing" and not "free choosing"?