Theologians have a range of perspectives on this question. Here is my take.
1) The church and the kingdom are not the same but are closely related.
2) Think of a timeline. On one end you have Abraham, in the middle you have Jesus on earth, and on the right hand end you have the return of Christ.
I see God’s goal — launched with Abraham was to have a people who would declare, “You are our God!” and over whom He could say, “You are my people!” As God adopts his family he goes from a tribal network to a nation to a church (people scattered among every nation) to the kingdom.
BUT — Jesus declared that with his coming as redeemer and the indwelling Spirit now in every one of God’s people we were to be living out kingdom lifestyle and values.
The lives of Christians should make people want to be in Jesus’ kingdom family. The power, peace, love etc., should all be evidence that the message of salvation in Christ is true and available.