So, what does that mean for Christians today? Well, the first thing it means--and we have stressed this repeatedly already--is that God keeps His word. He is faithful to uphold and fulfill His promises; He cannot lie (Titus 1:2). This should comfort us today, for example, in that we can be confident that since God promised that Jesus will return, then He absolutely will (even though nearly 2000 years have passed since His ascension). This promise, like all of the others God has made, will be fulfilled (at the proper time)!
But, what else do these promises to Abraham mean for Christians? Is there more to be fulfilled regarding them? I don't believe so. The value of these promises today is not prophetic but historical. We have considered biblical evidence that these three promises have been fulfilled completely. Therefore, it is unwise to construct any theory that would imply that God has not yet fulfilled his word to Abraham. Allow me to elaborate.
The nation promise has been fulfilled and the Jewish people are no longer God's special people. I mean no disrespect by that, but the Bible does teach that God's special people today are members of His church. Whether or not one is a physical descendent of Abraham today is irrelevant. What is important is that we are of the spiritual seed of that great patriarch (Gal. 3:26-29)! There are many passages that show that physical Israel would not always be God's chosen ones but that His people would compose a spiritual "nation" (please study Matt. 21:43; Rom. 2:28,29; 9:8; Gal. 4:21-31; 6:15,16; I Pet. 2:9,10). This new nation or kingdom--the church (Matt. 16:18,19)--was prophesied about and brought into existence (Isa. 2:2,3; Jer. 31:31-34; Dan. 2:36-45; Joel 2:28,29).
The land promise has likewise been fulfilled and physical Jerusalem is now of no more significance to God than any other place on Earth! The only "land" promise yet to be fulfilled is that of a heavenly home for God's faithful children today ("spiritual Jerusalem", if you will; cf. II Pet. 3:10-13; Rev. 21:1ff).
The seed promise has also been fulfilled and its benefits are still realized today when a person lost in sin obeys the gospel and becomes an heir "according to the promise" (Gal. 3:29).
Friends, although there are spiritual applications to these promises that were made to Abraham, it is foolish to expect further physical fulfillment of any of them (as premillennialists do). Many false ideas on this theme that are circulated today are a result of perverting Old Testament prophecies that have been fulfilled by attempting to make them refer to some future event. For instance, premillennialists will try to take prophecies that foretold the return from Babylonian captivity and the rebuilding of the temple, and make them refer to a future restoration of physical Israel (e.g., Eze. 37). They also try to take passages that refer to the church and make them apply to a future millennial kingdom on this planet. The key to defending against these false ideas is a careful examination of each context in conjunction with the rest of God's holy word (cf. Psa. 119:160).