If we just observe the life on our planet, we will find few behaviors, that are common to all lifeforms. The most important of those is reproduction. Everything else, like seeking food or fleeing from danger, serves to achieve the goal of reproduction. Some species even die after reproducing, because their life’s purpose has been fulfilled. Humans are no different. While we are sometimes able to not follow our desires, we do have them and they are the same as those of other animals.
From this we can conclude that the purpose of life is to reproduce. Purpose means there is a goal that should be achieved and reproduction is the goal that life is conditioned to achieve. However, this way we arrive at a circular reasoning of "life exists, so that it can exist". That is effectively the same as having no purpose at all.
This is not a problem. We exist just fine with such an empty purpose. As conscious beings, we can suppress our conditioning and choose a different purpose for our lives.
If we assume some conscious being (god) created life, either directly or indirectly (by creating a universe which allows for life to appear), whatever reason that being had for doing this gives a purpose to the life created. Some people may think themselves obligated to fulfill the purpose intended by their creator, but others may not, especially when the purpose involves a lot of undesirable things, like suffering. It is a question of ethics.
However, there are many religions in the world and each of them claims to know the truth, yet they contradict each other and the reality we observe. Therefore, it is most likely that all of them are incorrect. Which means that either there are no gods, or there are some and we don’t know anything about them or the purpose for which they created the universe.
Fortunately, it does not matter. If a universe is created for a certain purpose and it works correctly, whatever happens in the universe is fulfilling that purpose. As long as no gods directly intervene, we can do anything and be sure that we do it with full blessing of such potentially existing gods.
Finally, there is a question of life’s necessity, or the necessity of existence in general. If there was a reason why an universe (or anything else) must exist, it would mean the universe has a cause. However, the cause itself is something that has to exist too, so if we imagine that everything ceases to exist, then that would include the cause as well.
To put it differently, nothing existing is a perfectly valid state. Existence is neither inevitable nor necessary. The fact that we exist without a cause (or reason) is not a problem. At most we can conclude that life has no obligation to exist and create more life.