Some things that I have been thinking,
All the disciples without exception proved themselves unworthy. They all choose to allow Jesus to walk the Old Calvary Road by Himself, They all where offended by Him and they all scattered. That day they all Failed to take up their cross and follow Jesus to Golgotha.
The motivation to earn worthiness by taking up their cross and following Jesus was not and is not strong enough to overcome certain things.
Cain tried to appease Gods favor by the sweat of his brow and callus of hand, and it did nothing for him other than bring condemnation and Jealousy.
On the other hand Abel did nothing other than to almost effortlessly offer back to God, Gods own provision for him of the unspotted Lamb. Abel did this not from a heart to appease, but instead from a heart of gratitude.
The condemned and Jealous heart of Cain killed his brother Abel.
When our hearts are trying to earn worthiness by effort we are always critical and comparring ourselves to others, hating others instead of Laying down our lives for others
After Jesus laid down his life for us: We than see the disciples than being correctly motivated and empowered from a heart of Agape and Gratitude laying down their lives for the brethren.
They than where empowered correctly to deny themselves take up their cross and follow Him.
