Jesus Himself taught that His kingdom does not come with observation (Luke 17:20). But davy here teaches that it does come with observation. It's not hard to decide which position to accept.
The idea that the "Kingdom does not come with observation" does not mean the Kingdom is not coming *physically.* It means that carnal eyes cannot see the Kingdom's activity in bringing salvation to men and in preparing to bring judgment to sinners.
In Jesus' day, the Pharisees completely failed to see their inward sins, in particular their rejection of Christ. And they relied exclusively on their own works.
As a result, they could not "observe" the Kingdom operating through Jesus in front of them, because it is a limited form of God's Kingdom. They completely failed to see their own sins, as well as the sins of all Israel. Their expectations of the Kingdom were purely political and about external religious observance. But they lacked the ability to see the spiritual need and the fact Israel lacked that.
As such, the Kingdom can not be identified by that kind of observation. It is a spiritual insight that recognizes the Kingdom begins at present in limited form because the world is presently alienated from it.
But I believe this present activity of the Kingdom, which is mysterious and recognized only by eyes of faith, must be distinguished from the physical coming of the Kingdom. Jesus was not talking about that when he spoke of not being able to observe it *now.*