No, you can't force anyone into a religion. Where there is a state religion there is an economic advantage to voluntarily converting, but no one can see into our hearts. The Converso Crisis was the result of such incentivized ("forced") conversions. Fake conversion is skin deep and has no positive effect on society. Counterfeit Christians are always Judases in our midst.

When the pagans of Gaul converted to Christianity they lived the faith, fought for it and died defending it. They dedicated their lives to Christ and committed all their material wealth to the Church and to building fabulous churches. They wrote theological tracts, went on pilgrimages and kissed the rings of the bishops. Whatever the Church said was virtuous they pursued; whatever the Church declared sinful they avoided.

These ex-pagans loved the Church and organized their society around Her seasons and sacraments. They raised their children to be faithful Christians and good priests. The French peasantry is still very Catholic, even after 500 years of constant propaganda against the Church. The people who think they oppose the Church have no idea how much they owe Her and how much they will miss Her when they have purged Her from their towns. One taste of genuine paganism will teach them what their great-grandparents knew.

Conversos who did not fully or genuinely embrace Catholicism, but continued to practise Judaism in secrecy, were referred to as judaizantes ("Judaizers") and pejoratively as marranos ("swine"). They could not hide their lack of faith. The same is true of homosexual or otherwise liberal Christians. They have an anti-Christian axe to grind and their Sunday faith disappears the rest of the week. The European pagans who embraced Christ were great Christians and wonderful additions to the Church.