What is the ruling on a Muslim who declares their Christianity and goes to church to obtain citizenship in a Western country due to difficult living conditions, with the intention of remaining a Muslim in secret and revealing their Islam later?

Whoever outwardly manifests disbelief by their own free will, intellect, and maturity has committed an act of disbelief, even if they did not intend it in their heart, because the intention to acquire wealth does not permit disbelief. Nothing permits uttering disbelief except duress. And whoever utters disbelief voluntarily has opened their heart to it. This man must fear Allah and seek lawful sustenance, for Allah provides for those who fear Him from sources they do not anticipate.