We never know when our last day on earth will be. So, love with full sincerity, believe with true faith, and hope with all of your might. Better to have lived in truth and discovered life, than to have lived half heartedly and died long before you ever ceased breathing.
He who asserts belief with absolute certainty knows nothing of faith and makes himself into a fool. He who is wise, upon realizing they have done this, recants and searches themselves for further enlightenment.