What is the best way to worship God? Worship one or other form of God or an impersonal God without any form and shape?

This is one of the biggest questions across all religions since medieval and till modern times. But since Arjuna has asked this question in Shrimad Bhagvad Gita it proves this question existed in ancient times too.

Arjuna in this question asking Shri Krishna. Which devotee is better

1. One who worships You or

2. One who worships an impersonal invisible form

The question here points to the two existing schools of thoughts of devotees. The first set of devotees worship God as impersonal and invisible. This school of thought hence prohibits making any form of God and using any statues, image or symbol which represents God.

The other school of thought takes one or other forms of God and worships using all physical symbols, statues, and pictures. When Arjuna points the set of devotees who worship Shri Krishna, it points to a Shri Krishna as an entity that existed in Dvapara Yuga in the house of Vasudeva and Devaki. Though Shri himself is the supreme personality of Godhead as Shri Krishna he is the son of Vasudeva and Devaki, who born in Mathura, spend his childhood in Gokula and later in Mathura and Dwarka. When it is said in this Shlokas of devotees who worship Shri Krishna it automatically concluded worshipping the whole lifetime of Shri Krishsha Cause when devotee takes the form of Shri Krishna its not one, but all those from the time of incarnation till the King of Dwaraka. This set of devotees hence worship all the forms of Shri Krishna from the time of his appearance in the prison of Mathura till he was the king of Dwaraka. Every act of Shri Krishna hence is the source of devotion for this set of devotees. When such devotees worship Shri Krishna they present the Leela performed by Shri Krishna in statues, present it on stage, sing bhajans of those Leela, and so on.

This way of worship is what called Sakar Sadhana(worshipping God through a form). In modern times this term though not correct is used as idol worship. Though Hindus never used such term as “Idol worship” for two reasons. 1. It's not correct terminology nor does it present the worship methods of Hindus. 2. It is used mostly as a derogatory term by non-Hindus. But yes for those who still want to understand from this term “idol worship” the question is about which is better

1. Idol worship or

2. Worship of an invisible God without any symbol.

In the next 7 Shlokas Bhagvan Shri Krishna has given answer categorically and given clear reasons.