As you said, the two Ayas have exactly the same word, they are copycats.
There are two approaches to understand these ayat (and the context as a whole), both are acceptable, and both depend greatly on Arabic Language, they are:
Either there is a repetition in meaning itself, and so the translation should be exactly the same, and reasons for that repetition are available in the source I'll include below below.
Or there is no repetition in meaning, and the two ayas are different due to context, this bears three understandings:
- One is that the first two ayas refer to future and the second two ayas refer to the present time (or current state). The evidence is in the second aya { لا أعبد ما تعبدون }, it is that the negation tool "La لا" can come before verbs that are only present and refer to the future, this is because in Arabic there are no future form for verbs, future is represented in the present form plus a tool, and in this case, this tool is "La لا". So, the meaning becomes that I will not (in the future) worship what you ask me to worship, nor will you worship what I ask you to worship, this actually happened and they never became Muslims (see the revelation reasons of this Aya). Then he said (in Ayas 4&5) that I am not (currently, my state) worship what you worship, nor you worship what I worship.
- The second is the reverse (this is the situation in the question), the fist two ayas refer to the present time (and current state) and the second two ayas refer to the future. The evidence is in the 4th aya { ولا أنا عابد ما عبدتم }, it's that this sentence is a negation of the sentence أنا عابد ما عبدتم which refers to the future (I'm going to worship what you worship) because the "actor noun" عابد (actor noun is something in Arabic equal to the "doer form" in English, for example, make-> maker, sing->singer, and so on) in the context of the aya includes the meaning of intention, which refers to the future.
- The third is that each couple of ayas (2&3 and 4&5) can bear the meaning of present (current state) and future at the same time, but we specify one for current state and the other for future to prevent repetition. So if we say that he talked about state firstly, and then about future, then that is reasonable because he is following the order of times (present and then future); on the other hand if we say that he talked about future firstly, then that's because they (Mushrikeen) asked him to make a future deal with them (see the revelation reason of the Sura), and for that future is more important to talk about, hence talked about it firstly and then talked about the present.
Source of the above: Tafseer Al-Razi (or The Big Tafseer) Vol.32, P.145, By Imam Fakhr Aldeen Al Razi (may Allah be merciful to him).
There is also a very nice reasoning for the repetition in Asrar Al-Tikrar fi Al Qur'an (Repetition Secrets in Qur'an) paragraph #585, by Mahmoud Al-Karmani. But I'll not mention here because the question will become too complicated and may lead the reader to confusion.
In fact, this is a good example to see the miraculous wording of Qur'an, which Allah challenged Kuffar to get similar eloquence and wording. I thank you for asking this question and making me read that awesome tafseer by Imam Al Razi!