Jesus did not come to start a new religion, but to inaugurate the Kingdom of God. The K of G transcends all religions, denominations, and churches. It is the Empire of God that will eventually cover the earth. Whether you are a Jew, Muslim, or Christian, you are invited to enter it.
When sharing the Gospel of the Kingdom we are not trying to convert a person to Christianity, but to Christ, i.e. King Jesus. The kingdom stands above Christianity. Many people are church members and part of the Christian religion who are not part of the Kingdom of God. When witnessing we should be inviting people into the kingdom. The encounter would look something like this:
KINGDOM OF GOD
Judiasm Islam Christianity
The three bottom labels represent the group to which the lost person belongs. We are inviting them to pledge their allegiance (loyalty/fidelity) to King Jesus through baptism, having counted the cost of their decision.
Notice how this approach disarms those in all three categories. We are not asking the Jew or Muslim to join the Christian religion. Nor are we allowing the "Christian" to base his/her salvation on church membership or initial profession of faith. The nature of the Gospel of the Kingdom allows us to approach each group in an authentic way that catches each off guard.
In our presentation we do not equate salvation with heaven, but with a transference of allegiance from one earthly kingdom (to which all three "religions" belong) to God's kingdom. Once the transition takes place, the convert become an ambassador for God's kingdom, representing His kingdom to the world. Converts are funneled into newly planted voluntary associations (ekklesiai) where they eat and worship together and experience God's kingdom presence in their midst.