Start the square of Mars in Aquarius

Provided that Mars, at the moment you choose to start its material Square, is not placed in a sign of fall (Cancer) or detriment (Libra, Taurus), the spiritual working should proceed in due positive way.

Be mindful, however, that should there exist latent negative karma connected to your Mars and soul, and a carelessly or improperly worded affirmation might awaken it, and such energetic currents could then manifest upon the plane of reality (the affirmation may be deemed improperly formulated when it lacks a concluding positive formula/intent, such as “in all ways that are healthiest and most harmonious for me”, or similar expressions that help you directing the energy you raise toward a beneficent outcome aligned with your purpose).