Question: - Is the worship of God Vishnu not good?
Answer: - There is proof in Shrimad Bhagavad Gita Chapter 2 Verse 46 that the speaker of Gita has said – “O Arjun! After obtaining a very large reservoir of water (lake), whatever interest a person has got left in a small reservoir; the same amount of faith is left in other knowledge and the lower gods, after knowing the complete spiritual knowledge and the way of worship of the Complete God and the benefits obtained from Him. The same as is left in a small reservoir after obtaining a large water body.
The water of the small reservoir is good, but not sufficient. If it does not rain for a year, the water of the small reservoir dries up, and the people dependent on it bear hardships due to shortage of water. There is a cry for help. But the water of the bigger reservoir (lake) does not finish even if does not rain for 10 years.
A person, who will find such large reservoir, will immediately abandon the small reservoir (pond) and dwell near the bigger reservoir. When the knowledge of Gita was narrated, at that time all the people were dependent on the water of ponds. Therefore, this example was given.
Similarly, although you consider the worship of Shri Vishnu to be good, it does not lead to complete salvation. Shri Vishnu is also mortal. He also has birth and death. Then how can his worshipper be immortal? Therefore, to attain complete salvation, that is, to become immortal, one would have to worship the Immortal God only.