delta_G_{standard} = -RT ln(K) = -$nFE_{standard}$. These three quantities are interconnected: if $delta_G$ < 0, then K > 1 and E > 0 (spontaneous forward reaction). If $delta_G$ > 0, then K < 1 and E < 0. At equilibrium: $delta_G$ = 0 (not delta_G_{standard}). delta_G_{standard} tells us about standard conditions; $delta_G$ tells us about actual conditions. $delta_G$ = delta_G_{standard} + RT ln(Q). When Q < K: $delta_G$ < 0 (forward). When Q > K: $delta_G$ > 0 (reverse). When Q = K: $delta_G$ = 0 (equilibrium).