Secularism wants to protect your right to hold and practice any religious belief you wish to take up;
How does it propose to do this?
How is it doing this at the moment?
By guaranteeing freedom of religion, and freedom from religion.
And by ensuring that people don't suffer discrimination on the basis of their religion or lack thereof, nor are they afforded special privileges on the basis of their religion or lack thereof.
Simples.
How is it doing this at the moment - well in the UK, reasonably well, but there remain certain obstacle to those goals, mainly situations where people with a particular religion are afforded special privileges not afforded to others who do not hold that religion. And if you turn it on its head, that is in fact discrimination against those who do not hold that religion.
Secularism is in no position to guarantee anything. It cannot guarantee that it will champion supporting religion in any sense.
Like religion, it can only come to some kind of compromise and to keep watching itself for signs of it's own potential excesses.
Once you realise this then the slogan freedom of religion and freedom from religion looks like what it is, contradictory with freedom from religion only possible through suppression and some kind of apartheid.
Where you are coming from, The notional secular state is the equivalent of a theocracy.
Your view is therefore sentimental since it assumes the slogan will happen automatically and that secularists are somehow automatically virtuous when in reality, like religion, Secularism must be constantly vigilant....against it's own dark potential.