One who worships the deity must be non-envious

7.14.40:
Sometimes a neophyte devotee offers all the paraphernalia for worshiping the Lord, and he factually worships the Lord as the Deity, but because he is envious of the authorized devotees of Lord Viṣṇu, the Lord is never satisfied with his devotional service.

From the purport:
Deity worship is especially meant for purifying the neophyte devotees. Actually, however, preaching is more important. In Bhagavad-gītā (18.69) it is said, na ca tasmān manuṣyeṣu kaścin me priya-kṛttamaḥ: if one wants to be recognized by the Supreme Personality of Godhead, he must preach the glories of the Lord. One who worships the Deity must therefore be extremely respectful to preachers; otherwise simply worshiping the Deity will keep one in the lower stage of devotion.