Commentators like Charles Spurgeon call this an 'invincible argument' for the Christian's security. The logic is: if God did the most difficult thing imaginable—reconciling us when we were His enemies through the apparent weakness of Christ's death—how 'much more' will He do the comparatively easier thing of preserving us now that we are His friends through the power of Christ's resurrected life? Our future salvation is even more certain than our initial reconciliation.