[Assuming we are still talking about 2 Pet. 1] No. Peter does not say theosis/salvation ITSELF is assured by works, rather he says that the believer can know what is already assured in fact. It appears you are zooming in on verse 10 :
2 Peter 1:9-13 : 9 But if anyone does not have [the earlier listed good traits/deeds], he is nearsighted and blind, and has forgotten that he has been cleansed from his past sins. 10 Therefore, my brothers, be all the more eager to make your calling and election sure. For if you do these things, you will never fall, 11 and you will receive a rich welcome into the eternal kingdom of our Lord and Savior Jesus Christ. 12 So I will always remind you of these things, even though you know them and are firmly established in the truth you now have. 13 I think it is right to refresh your memory as long as I live in the tent of this body, ...
Verse 9 says "he has been cleansed", past tense, already done for all time in accordance with God's other promises in scripture. He is saying the believer can "forget" this, which is true. Not all believers "remember" the fact of their salvation. Doing works DOES help those believers to "remember", and in any event doing good works grows the faith of the believer. Verse 10 obviously builds on verse 9, "do good works to avoid being one of those who has forgotten that he has already been cleansed". Verse 12 further confirms the idea. Peter knows that we are easily forgetful (how true!) so he will remind us even though we should already know better. How many times do we need to be reminded of simple Biblical truths. Speaking for myself, PLENTY. :) At the beginning I used to wonder why there was so much relative repetition in the Bible. I wonder no longer. :)
Actually 10 and 11. The two go hand-in-hand. They are part of one sentence (remember that verse nuimbeirng is man-made and that it was done for ease of reference only). The sentence reads:
Clearly, he is associating the works with receiving a "rich welcome" into Christ's kimgdom. The conditional nature of his statement is clearly makred with the word is if.
If is not a guarantee. Yes, we have bene cleansed, but if
Completely innatural reading altogether. The plain meaning of it is that the work of santification makes election sure, not makes the memory of ir sure. Also, the reference to forgetting is to the "past sins". The implication is clear that should one called to Christ fail to do all these works AFTER the past sins have been cleansed, he will not be among the elect.