What is the ruling on remaining in a state of ritual impurity (janabah) for three days without performing ghusl (ritual bath), despite the availability of water?

Willfully abandoning prayer is a grave sin, greater than adultery and theft, and so is praying while in a state of ritual impurity (janabah).

Sincere repentance is obligatory, as is making up the prayers from past days, for they are a debt upon one's conscience.