It is never too late to believe in Jesus. It is never too late for us to put our trust in Jesus. It is never too late for us whenever we put our trust in Jesus. You see, when everyone else concludes that is it too late, there's Jesus. When you yourself might have only the last gasp of a prayer, that's enough if the prayer is addressed to Jesus.
The invitation of the Lord himself is simple and consistent:
"Believe in me."
Not generic religion
Not some sort of pretending to be true things that aren't really true.
Faith: durable trust in the One and Only, the Way, the Truth, and the Life.