Deciding on criteria for immigration admittance in no way represents an establishment of religion.
I notice that you ignored my real life concrete example which shows why these ridiculous laws are unconstutional.
So, I will repeat
Trump says that If I am a Christian American citizen of Syrian origin and want to bring my christian family here, I have a preferential treatment compared to a Muslim American citizen of Syrian origin trying to bring his Muslim family in the US.So, in essence, the federal government pressures people to adopt Christianity in order to get a different treatment. Tactics of these kind DE FACTO establish a religion.
Now, try to explain how the above result fits with the beginning of the first Amendment
Congress shall make no law respecting an establishment of religion.
I also used in the beginning and now the word DE FACTO.
I assume what you try to say is that these laws do not DE JURE "respect an establishment of religion," meaning do not officially designate respect for a particular establishment of religion. This is correct and also 100% irrelevant! As long as there are de facto (or in practice) different federal penalties or rewards for particular religions, the government in practice promotes a particular religious establishment!
And we have SCOTUS decisions making very clear that De Facto consequences that violate the Bill of Rights are prohibited. The classic case was segregation laws which created DE FACTO inequality even thought they did not De Jure (officially) designate that blacks and whites were not equal. In fact, they were officially using the doctrine of "separate and equal"!