John 13:36-38 (ESV)
Simon Peter said to him, “Lord, where are you going?” Jesus answered him, “Where I am going you cannot follow me now, but you will follow afterward.” Peter said to him, “Lord, why can I not follow you now? I will lay down my life for you.” Jesus answered, “Will you lay down your life for me? Truly, truly, I say to you, the rooster will not crow till you have denied me three times.
Simon Peter is all in for Jesus, but does not, yet, know his internal weakness. That is so true for all of us. Until tested we are not guaranteed we can still do what we thought we could do. There is no doubt the Peter is sincere in the above commitment. He just lacks the understanding about his own, true nature. Paul would say it this way in his letter to the Romans:
Romans 7:14-18 (ESV)
For we know that the law is spiritual, but I am of the flesh, sold under sin. For I do not understand my own actions. For I do not do what I want, but I do the very thing I hate. Now if I do what I do not want, I agree with the law, that it is good. So now it is no longer I who do it, but sin that dwells within me. For I know that nothing good dwells in me, that is, in my flesh. For I have the desire to do what is right, but not the ability to carry it out.
Like Peter we want to say we would follow Jesus, even to our death. But the flesh is not as strong as the spirit in us. This is why we must rely completely in God’s grace.
1 Corinthians 15:10 (ESV)
But by the grace of God I am what I am, and his grace toward me was not in vain. On the contrary, I worked harder than any of them, though it was not I, but the grace of God that is with me.
James 4:13-17 (ESV)
Boasting About Tomorrow
Come now, you who say, “Today or tomorrow we will go into such and such a town and spend a year there and trade and make a profit”— yet you do not know what tomorrow will bring. What is your life? For you are a mist that appears for a little time and then vanishes. Instead you ought to say, “If the Lord wills, we will live and do this or that.” As it is, you boast in your arrogance. All such boasting is evil. So whoever knows the right thing to do and fails to do it, for him it is sin.
We do not succeed because we boast with our mouth to succeed. We succeed by believing in our hearts that God will produce within us, by His grace, what He needs from us.
Hebrews 13:20-21 (ESV)
Now may the God of peace who brought again from the dead our Lord Jesus, the great shepherd of the sheep, by the blood of the eternal covenant, equip you with everything good that you may do his will, working in us that which is pleasing in his sight, through Jesus Christ, to whom be glory forever and ever. Amen.