I'm a Christian and here is my assessment of the nature of faith.
Everyone lives by faith. When you decide to get in an airplane, you go by faith that the plane is sound, the pilots are skilled, etc. Same idea with driving to work, picking a job, getting married, conducting an experiment. By virtue of the fact that no one knows the future, we all must at the most basic level, live by faith.
Faith is commitment without knowing (with 100% certainty).
Of course that does not mean faith has to be blind and irrational. You make observations about the world, hear testimony of people you trust, think through the issues and come up with your conclusions.
Atheists weigh the evidence (e.g. if God exists, why is there so much evil? Or why does God not reveal Himself more clearly?) and don't see God.
Theists weigh the evidence (e.g. why is there something instead of nothing at all? or observe the improbability for the conditions that allow life in Earth) and see God.
Blanket accusations that theists having no rational basis for their beliefs are not fair. There is rational basis for either camp if one is open to honest researching and listening.
Throughout the ages there were and are great rational thinkers who profess faith in God. (e.g. Blaise Pascal, Isaac Newton)
This is to say again, everyone lives by faith. I have great confidence that God exists, but can not 100% prove it. The atheist can not prove He doesn't. I concede that I could be totally wrong. A rationally honest atheist will concede the same about their own beliefs.
So we all make a decision.
Our death is the day of reckoning. Only then will there be the possibility to know for certain if what you have chosen to believe was right or wrong.[0]
TLDR; In issues of existence of God, afterlife, etc and therefore meaning, we cannot know for certain either way. So make the best choice you know how and we'll all find out if we were right later.
[0] Technically, in the case that I'm wrong (about the afterlife), we won't know much of anything.