State: No Religion, False Religion, Christian
A State may either have 1) no religion, be that of a 2) false religion, or be 3) Christian. It would seem that Christians would advocate for the State to be Christian. (Note that there may be a further disagreement about which Christian religion is true, versus false Christian claimants: Catholicism versus Orthodoxy versus Protestantism, etc.)
Abortion Example
Consider the example of abortion: if there is 1) no religion, the people may be "free" to have abortions. Christians would not support this. Likewise, a 2) false religion might assert a right to abortions. Hence a Christian would not support a false religion in doing this. Therefore there would be a tendency of Christians to want the State to reflect Christian values, or to be 3) Christian.
Israel: No Religion or Christian?
There are some who identify as Christian who advocate for there to be 1) no state religion. Assume for the sake of argument that this is an acceptable position to take: then, they would advocate for Israel to not be a religiously Jewish state. If they 3) advocate for Israel to be Christian, then they also wouldn't advocate for Israel to be a religiously Jewish state, and it would seem irrational for a Christian to advocate for a state to be 2) religiously Jewish (considered to be a false religion from the Christian perspective) rather than 3) Christian.
Hence those who identify as Christian would only advocate for Israel to be 3) Christian, or 1) to have no religion; in neither case would they advocate for 2) Israel to be religiously Jewish (which is considered to be a false religion, from the Christian viewpont).
Conclusion
Therefore, is it not impossible for Christians to be Zionists, or to want the state of Israel to be religiously Jewish?
Why, I’m glad you asked.
>Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ. **~ Galatians 3:16**
>And if ye be Christ’s, then are ye Abraham’s seed, and heirs according to the promise. **~ Galatians 3:29**
>Whosoever denieth the Son, the same hath not the Father: (but) he that acknowledgeth the Son hath the Father also. **~ 1 John 2:23**
>It was necessary that the word of God should first have been spoken to you: but seeing you put it from you and judge yourself unworthy of everlasting life, we turn to the Gentiles. **~ Acts 13:45-51**
>O Jerusalem, Jerusalem, thou that killest the prophets and stonest them that are sent unto thee, how often would I have gathered thy children together even as a hen gathereth her chickens under her wings, and ye would not! Behold your house is left unto you desolate. **~ Matthew 23:37-8**
>Therefore say I unto you, The kingdom of God shall be taken from you, and given to a nation bringing forth the fruits thereof. **~ Matthew 21:43**
>There shall be weeping and gnashing of teeth, when ye shall see Abraham, and Isaac, and Jacob, and all the prophets, in the kingdom of God, and you yourselves thrust out. **~ Luke 13:28**
>The Jews, who both killed the Lord Jesus and their own prophets, and have persecuted us: and they please not God and are contrary to all men: forbidding us to speak to the Gentiles that they might be saved, to fill up their sins always: for the wrath is come upon them to the uttermost. **~ 1 Thessalonians 2:14-16**
>Behold, I will make them of the synagogue of Satan, which say they are jews, and are not, but do lie; behold, I will make them to come and worship before thy feet, and to know that I have loved thee. **~ Revelation 3:9**