Is the weakening of faith and the laxity in worship after the injury that prevented going to the mosque a result of praying at home, or is it a test of faith?

If illness prevents a Muslim from going to the mosque, there is no blame upon him for missing congregational prayers, as stated in the hadith (definition): "Whoever hears the call [to prayer] and does not come, there is no prayer for him except for one with an excuse." The ill person is advised to compensate for this by reciting the Quran, performing dhikr (remembrance of God), studying books of hadith and seerah (definition) (Prophet's biography), staying away from sins and idle amusements, and encouraging visitors towards good.