my view is if one has already been given eternal Life, then sin and repentance are an issue of Fellowship, not SalvationAGREED, this is why I invest in two words in this Grace that we live in.... A. "Relationship", and B. "Fellowship".
David's sins effected his fellowship with his fellow Israelites and with his God within that covenant, but
he was already expecting a place with God forever
God prophetically said He would provide the necessary Blood
but like in Egypt
one must believe and trust what God said, and it must be Applied to get the promised benefit