"Is it necessary to be baptized to obtain eternal salvation?" - This is a question that arises frequently, and I recently encountered it again. If the answer were one word, then yes, it is necessary. But this one word leaves out a number of other questions that inevitably arise - and that are worth considering in more detail.
The question of baptism and salvation is related to two others - "Do you believe in eternal salvation?" and "Do you want it?"
If eternal salvation is real, then it is the most important thing that can possibly exist. Imagine that all of this is reality: you were created by a loving God for eternal joy, love, glory, and beauty that surpasses anything we can conceive of here on earth. That all the good, noble, and beautiful things we know on earth are distant reflections of the eternal light that we can enter into - and are invited to enter into. That all earthly sorrows and woes will be turned into immeasurable glory and comfort, that the deepest needs of our hearts - so deep that we often dare not admit them - will be satisfied, and that we will be eternally and infinitely happy.
In this context, the question "do I need to perform certain actions aimed at seeking eternal salvation - such as being baptized, changing my way of life, and joining the Church?" simply loses its meaning. If we are talking about something so important, we are not looking for an economical way that would allow us to reach our goal with the least amount of effort. We are looking for a reliable path.
People save effort on something they do not consider important. If it works out, great, if not - well, it wasn't that important anyway.
But if we are talking about eternal salvation, saving effort and asking "can I do without baptism?" is simply ridiculous. Even if we were talking about our temporary life - for example, a dangerous illness - we would not think about how to heal ourselves more cheaply. We would be interested in how to heal ourselves for sure.
Another question we must answer for ourselves is whether Jesus is our Savior. Is what He says about Himself in the Gospel true? Is He really the One He claimed to be - God, Savior, Judge, the Only One who can give us eternal and blessed life?
If this is true - and it is - then the question of baptism before me is not posed by the Church, as a group of people, but by God Himself. The Creator and Ruler of this universe became a human being, just like us in everything except sin, lived a human life, and accepted a human death - a terrible death - for my salvation. How can I respond to this? To accept His gift in the way He Himself established. To be baptized and enter His Church.