His own love (tēn heautou agapēn). See note on Joh 3:16 as the best comment here.
While we were yet sinners (eti hamartōlōn ontōn). Genitive absolute again. Not because we were Jews or Greeks, rich or poor, righteous or good, but plain sinners. Cf. Luk 18:13, the plea of the publican, “moi tōi hamartōlōi.”