We are eternal beings and this is why we ask intelligent questions about de beyond the here and now.
You ask for people to tell you if they've seen anything to make them believe in life after death. I'd say I have. I'd say we all have, which is why we consider the big question that you're considering here.
The bible says God shows us his invisible attributes, and shows himself through nature all around us. You often here of people saying they've been skiing and looked actors the show capped mountains and felt in awe, and a sense that this could not have happened by accident. Or a sunset, or a peaceful feeling, or the deepest love between parent and child. Or undeserved forgiveness. All of these are portrayed in our relationship with God.
We all know we have done wrong at some point in life, and to varying degrees we've felt guilty, often for a good reason. But not everyone has the privilege of knowing these wrongs are erased and forgiven, and a fresh start has been allowed. We don't need to just wait for the afterlife for a true relationship with a God who loves us more than anyone else possibly can; it can start in this life, in the here and now.
I find this compelling as much as I find the truth of the bible irrefutable. It's accurate historically, archaeologically, medically and emotionally, spiritually, psychologically. Even the writings are better reading often than Shakespeare (which I very much enjoyed at school!).
So yeah, I'm convinced. I am at my most peaceful and best when I turn to my creator and face life with him, rather than the times I've turned my back and tried to go it alone in rebellion.
Speaking of rebellion, it's the only reason we turn away from God. We do so well to turn towards him instead. The best thing is it's all about what Jesus did for us because he died for us (the wages of sin is death, but the free gift of God is eternal life) and it's not what we can do to save ourselves. So best not to even try!