The "better land" is the land or country that the author of Hebrews mentions in Heb. 11:16, but in Ephesians, Paul speaks of "heavenly places." It seems this is the same thing. Paul often speaks of being "in Christ" and since Christ is in heaven, in the throne of his Father, the saints also have a place in heaven, hence the reference to "heavenly places." Here I will look at each of the verses in Ephesians where this occurs. They are as follows.
Blessed be the God and Father of our Lord Jesus Christ, who hath blessed us with all spiritual blessings in heavenly places in Christ:
Which he wrought in Christ, when he raised him from the dead, and set him at his own right hand in the heavenly places,
And hath raised us up together, and made us sit together in heavenly places in Christ Jesus:
To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God,
The phrase Paul uses is ἐν τοῖς ἐπουρανίοις and this expression also occurs in Eph. 6:12, though the English translation is a bit different, in the KJV, "high places."
For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places.
It is significant that the very same expression is used here, as in the four previous references. The "spiritual wickedness" must refer to the flawed teachings and beliefs that hold people captive even after they come into the church and believe the gospel. Besides these, there are "rulers of the darkness of this world." These are not flesh and blood enemies but spiritual ones.
There are several prophecies that speak of invaders coming against Jerusalem, and the land of Canaan which represents the spiritual inheritance of the saints, and the "camp of the saints," and "the beloved city." Mount Zion, and Jerusalem were raised up, and established in the top of the mountains, when Jesus ascended to heaven, as foretold by Isaiah. [Isa. 2:2] These prophecies of an invasion apply to the heavenly places which the saints inhabit, in a spiritual sense.
Those who try to apply the invasion prophecies (Ezek. 38-39, Zech. 12, 14) to modern nations are misguided, IMO, as these scriptures depict spiritual conflicts in the "better land" of the saints, in a figurative way. The land which is invaded in Ezekiel 38 is called "the land of unwalled villages." This could hardly apply to the modern Jewish state, and the Israeli West Bank Barrier thwarts the interpretations of Zionists and dispensationalists, who have claimed that the prophecy of Ezek. 38 depicts a Russian-led invasion of the Jewish state. Even former US President Reagan believed this. It is clearly a flawed interpretation.
Similarly the gathering of all nations against Jerusalem in Zech. 14:1-2 applies to the heavenly Jerusalem, not the earthly city. People have been taken captive in tens of thousands of different sects and denominations. This prophecy applies to the church, and helps us to understand its present condition.
In Ezekiel 36 the "mountains of Israel" are possessed by the heathen, and "are taken up in the lips of talkers, and are an infamy of the people." The mountains of Israel represent the spiritual blessings and promises of God to the saints, which have been misrepresented.
The war described in Revelation 12 is a parallel prophecy. Here, John describes it as warfare between angels. The saints are not to be at war with each other, but there is a spiritual war going on, a struggle to understand and come to the truth. In the warfare in Revelation 12, it is the saints who overcome the dragon. "And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night. And they overcame him by the blood of the Lamb, and by the word of their testimony; and they loved not their lives unto the death." [Rev. 12:10-11]
Verse 8 says of the dragon and his angels, when they are cast out, "neither was their place found any more in heaven." There is no place for delusions in the better land, and it represents the spiritual things promised to the saints. One of these is the promise that the Spirit will guide us into "all truth."
Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come.