As with the other churches, the promise that Jesus gives is connected to the future life of believers. This future life is referred to in the illustration of the white stone. It may also be referred to by the illustration of the hidden manna. We will think today about the reference to manna.
Manna was the bread sent from heaven in a miraculous way as provision for the children of Israel as they travelled through the wilderness from Egypt to Canaan. This heavenly provision was a picture of Jesus as the bread of life (John 6). So Jesus here could be saying to the believers in Pergamum that he would supply their spiritual needs.
Some manna was kept in the ark of the covenant, and from that point of view could be regarded as hidden. Yet it could also be regarded as hidden in that no one knew where the original manna was kept – it was hidden, but it appeared when needed. In a far higher sense, spiritual provision is hidden in heaven and is sent to believers when required.
Therefore, in the context of this letter, the hidden manna is the opposite of the temple meals that the compromisers in Pergamum were participating in. Those meals led to sin whereas spiritual provision from Jesus leads to holiness.
The difficulty with saying that this applies to the present is that Jesus promises it to the overcomer, which suggests that he is referring to what happens at the end of life and therefore to what will happen in heaven. He could be stating that believers should overcome daily (the manna was provided daily for Israel in the desert). If he is referring to a future heavenly experience, he is stating that one of the activities of heaven will be to feed on Jesus and all the resources that are found in him.
Both an earthly and heavenly experience could be covered by the reference to manna. And both kinds of experience point to the centrality of Jesus for believers, whether on earth or in heaven.