Hello
@frankalexanderberg1985
Some good questions there. I hope you allow me share my view on the matter.
First of all, concerning cell replacement: consider a waterfall, river or sea. We identify these bodies as localised, whether it be Angel Falls, Thames River or the Pacific Ocean. Even though their nature is transient, they have a locality and "presence" that can be seen and identified.
You are much more than passing water in a river. And despite how your body changes and grows, the people in your life know who you are and can identify you. Some aspects of your physicality are transient, but you are more than your skin, nails, hair or cells.
Secondly, let's address eternal life. Do not get confused by popular Christian teachings which are based more on man-made traditions and not the Scriptures themselves. The Scriptures teach us that the life to come looks like this...
Following the Messiah's second coming, New Jerusalem arrives on earth. A great city of an expanse covering most of the Levant. The elect who live in this city do so for up to 1000 years in the Messianic Kingdom. This will be a good life as we have been promised by Yahweh (God) that we didn't get in this crooked and fallen world. We will have empowered versions of our bodies there that can sustain long-life (as the patriachs of old) and it seems the fruit and vegetation there will have miraculous properties in assisting with this.
After this 1000 year reign, then eternal life begins upon a New Earth to be inherited by the elect. From additional books found with the dead sea scrolls, it seems our bodies go through a transcendence at this stage and we become like the stars of heaven. Bodies of light that can be changed at will and liberated from the shackles of decay and degeneration.
At least, that is what my studies have taught me.
You're mixing two trains of thought here, which will make matters complicated for you I fear.
If you believe in the Bible, then evolution has no place.
Evolution is indeed a theory with no significant evidence to support it. It's worthwhile spending time investigating this yourself. Do not take the "We have proven..." and "they now know..." claims lightly. Do not give respect to men just because they wear labcoats or letters after their name. Rather, investigate for yourself and see if you are being provided are reasonable theories or wild interpretations based on assumptive principles.
I used to be an atheist - a hardcore one. I believed in the whole big bang and evolution spin too. But when you take nothing for granted and investigate, you see just how poor the theory is and without any evidence but rather a bias interpretation of observable facts.
So anyway, I can't answer this one for you my friend as it's based upon the assumption that evolution is a thing.
Nevertheless, some interesting questions there! Keep on asking and searching - it's the only way to find the truth on a matter.
Love & Shalom