Having said that worship of the personal form is the best, *Shree Krishna clarifies that He does not reject the worship of the formless.* Those who devote themselves to the all-pervading, indefinable, unmanifest, inconceivable, immovable, eternal Brahman, also attain God.
https://www.holy-bhagavad-gita.org/chapter/12/verse/3-4
Question : *What does Shree Krishna promise to those who successfully worship the "Achyutam" (the Indestructible/Unmanifest) while being dedicated to the welfare of all beings?*
☀️ They will be granted worldly riches and a long, healthy life.
🌈 They will eventually be reborn as powerful celestial gods in heaven.
🍃 They also reach "Me" (the Supreme Lord), just like the devotees of the Personal Form. C
🐚 They become masters of the material elements and gain mystic powers.