Asking how your spiritual life is going will lead to evaluating your prayer life and devotional habits. Those questions will probably lead to a very discouraging answer of not well enough, or not as good as it should be.
Instead try these suggestions from John Ortberg in The Me I Want To Be:
“Am I growing more easily discouraged these days?”
“Am I growing more easily irritated these days?”
Both questions refocus the discussion on growth – are you making progress. The first question focuses on whether your level of peace is growing. If you are growing in peace, you will be less easily discouraged. The second question focuses on love. If you are growing in love, you will be less irritated with things and more tolerant. Both questions invite dialogue, not measurement against some unattainable goal.
Pr. Ortberg credits the questions to an unidentified person. I heartily recommend the book, by the way.