This shloka reveals something extraordinarily generous. Whatever form of the divine a devotee chooses to worship — any deity, any aspect — Krishna Himself strengthens that person's faith. He does not undermine it. He does not redirect it. He makes it unshakable.
Like a grandfather who sees his grandchild enthusiastically pursuing any good endeavor and quietly encourages it. The child may be drawn to music, another to craftsmanship, another to study. The grandfather supports each one in their chosen direction.
The foundation of all devotion is shraddha — faith. Wherever sincere faith exists, the divine's power is at work behind it. This shloka affirms that no sincere worship goes unsupported.