If they continue not in their unbelief (ean mh epimenwsi th apistiai). Third class condition with the same verb used in verse Romans 22 of the Gentile. Locative case of apistiai here (same form as the instrumental in verse Romans 20 ). For God is able (dunato gar estin o qeo). See this use of dunato estin in Romans 4:21 rather than dunatai. This is the crux of the whole matter. God is able.