Rodzimowierstwo is strong in Poland thanks to Zadruga movement, which influenced further, later organisations, like Toporzel, Zrzeszenie Rodzimej Wiary, Trygław and Niklot, which will never allow pagan legacy of Slavs to die in Poland.
For Poland, I would wish for Stachniuk's (creator of Zadruga) works to spread among Polish youth and for it to be implemented on societal level. There is so much beauty and peace that comes with this culture, that I believe it could only succeed.
Since Poland is brutally Catholic, key for their acceptance would be to show them how many Polish/Catholic traditions have pagan roots and traditions, especially central themes like Christmas in Poland and its Northern Heathen roots!
Bond between our countries? I will tell you only this, Puchacz, were it not for schism in Christian denominations (Orthodox vs. Western) and later Islam (in case of Bosniaks, Pomaks, Torlaks, Gorani etc.), none of this terrible wars (like Times of Troubles in Russia thanks to Polish Vatican fanaticism, where millions of Russians died, and then Russian wars of revenge afterwards that claimed millions of Polish lives, and which poisoned our relations terribly until even today, or for example Yugoslav Wars where millions of Serbs, Croats and Bosnians were slaughtered in 90's wars or during WWII, thanks to Orthodox/Catholic/Muslim allegiences of peoples involved in all those conflicts) would have happened. Russia and Poland would be brothers today, all Southern Slavs would be brothers today, if we had all maintained original Slavic faith, something that truly bonded us all.
Perhaps if all Slavic countries maintained ONE denomination of Christianity, things would have looked different, but this did not happen.
Instead, it turned out like:
Amazing how Europeans were able disagree so much over book written by some old jews that MILLIONS of their kin died.
2) A possible way to set up Slavic old faith as the national religion.
Hehe, this is hard part. As I said before, there would have to obviously be serious movement first, which then could challenge Vatican authority in Poland by showing how much Slavic pagan tradition can be found in Polish Catholicism, to show that church simply came and corrupted original faiths in order to gain control of Polish population of those ancient times. Rest was pretty much summed up well by comrade Pentaz earlier.
Let's face it, among Northern Slavs, who are most powerful and influential two countries? Russia and Poland (maybe Ukraine). In South Slavs? Serbia and Croatia (maybe Bulgaria). Without those denomination boundries removed, what stand in way of full Slavic brotherhood and unity?
After all, all it takes is certain number of registered followers, and it stops becoming cult, rather registered and one of official religions.
Question is finding enough followers to get it started.