I’ve been blessed to be taught that Jesus did before He taught, and how, at the very onset of His ministry, “it was quite apparent that He was living everything He was saying” (Matthew 7:29 Message paraphrase). It’s amazing to me to meditate on this statement at the end of the Sermon on the Mount, and to ponder how Jesus had already put into practice all that He taught there. That’s where His authority came from: being under the authority of His Father, first as a doer of the Word. 
One thing in particular that has touched my heart is to consider His statement, “blessed are those who mourn.” It’s wonderful to see how Jesus mourned during His life on earth. 
Some might mention “Jesus wept,” and His human feelings of sadness at Lazarus’s death as evidence that He mourned. Others might mention how He mourned over Jerusalem, that they were unwilling to come to Him. And I think there’s definitely truth to those perspectives, that Jesus’s mourning heart is demonstrated in His love for His friends, and for sinners. 
But my understanding is that this is not the kind of mourning that He’s especially encouraging in the sermon on the mount, when He says that those who mourn will be blessed. Here, He is speaking of a lifestyle of mourning as a source of continual blessing. “Blessed are those who (presently, continuously) mourn,” not, “Blessed are those who have mourned (at some point in the past).”
What we believe He is speaking about primarily is the spiritual law that those who mourn over their sin — who grieve over their falling short of God’s glory — they will be comforted. “"I will gather those who grieve about the appointed feasts- They came from you, O Zion; The reproach of exile is a burden on them.” (Zephaniah‬ ‭3:18‬)
But we know that Jesus was “without sin,” so surely He didn’t mourn like this? Interestingly, the very verse that tells us that He was “without sin” also unlocks the secret to why Jesus mourned. “For we do not have a high priest who cannot sympathize with our weaknesses, but One who has been tempted in all things as we are, yet without sin.” (Hebrews‬ ‭4:15‬) He was tempted just like us, and that’s why Jesus mourned! It goes on to say, “In the days of His flesh, He offered up both prayers and supplications with loud crying and tears to the One able to save Him from death, and He was heard because of His piety.” (Hebrews‬ ‭5:7‬)
It’s a shame that the crying over Lazarus comes more quickly to my mind than the daily crying of Jesus when faced with the suffering of temptation. And it is a great challenge to my heart to compare myself to Jesus in this. Do I mourn over being tempted? At the very threat of being separated from God, which is essentially what every temptation represents? I find that it is much more natural to mourn after temptation, over falling into sin. And we should definitely do that, but... but! I hear the Voice of the Lord calling, “Come up higher!” The Lord wants to lead us into such a life that we mourn the very presence of temptation. That we hate it. 
Why should I hate temptation itself? It’s easy to think that temptation is something outside of me, but James tells us that it’s actually evidence of something inside of us! “But each one is tempted when he is carried away and enticed by his own lust.” (James‬ ‭1:14‬ ‭NASB‬‬) We definitely don’t need to condemn ourselves when tempted — because there’s a difference between being tempted, and sinning — but do I must always remember that the very temptation reveals something inside of me that is capable of conceiving sin with the various temptations out there. That’s the picture James uses: it’s like an external enticement is the sperm, and my own lust is the egg. If I had no eggs, no sin would be born! The very fact that there’s something to fight is evidence that there’s something in me that can conceive sin — my flesh — and the more I grow in the image of Jesus, the more I will hate the presence of that flesh, which is revealed through a temptation. 
No temptation exists where there is no inward desire. So every allurement or enticement is in a sense a reminder of this sinful flesh which is hostile to the Spirit of God (Romans 8:7). I want to grow in my hatred of anything in me which is in conflict with God, and every time I become aware of a temptation, even if I overcome it, I am still reminded of that flesh. That’s why I should hate, and mourn, temptation itself. 
Jesus, when the disciples asked Him to teach them to pray as He did, taught those disciples to pray, “please Lord, don’t let us be tempted.” Do you pray that prayer? Jesus did! Jesus, Who knew the eternal destiny at stake in His life, did not want to be tempted! He asked God to protect Him from it, and He commanded His disciples to ask God as well. And if I compare myself with Jesus here, I have to admit, I don’t hate temptation nearly as much as He did. As I said, it’s more natural for my mourning to FOLLOW my falls. Rarely do I mourn the strain of temptation, the eternal threat that it poses to my spiritual health and destiny, like Jesus did. 
And how lightly I take temptation shows how little I fear the Lord. The fact that I’m so used to it, I take it in stride, shows how acclimated I am to the presence of evil, and to the potential of interrupted fellowship. Look at what it says about Jesus:
“The Spirit of the LORD will rest on Him, The spirit of wisdom and understanding, The spirit of counsel and strength, The spirit of knowledge and the fear of the LORD. And He will delight in the fear of the LORD, And He will not judge by what His eyes see, Nor make a decision by what His ears hear.” (‭‭Isaiah‬ ‭11:2-3‬) Of all of the marks of the Holy Spirit’s anointing upon Him, the thing that brought Jesus the greatest delight was that it produced a reverent fear of being separated from, or even ever hurting, His Father. I need to delight in such fear!
Hebrews 9:28 is an incredibly encouraging verse in the face of all these shortcomings: “(Christ) will appear a second time for salvation without reference to sin, to those who eagerly await Him.” Jesus will return and make no reference to sin to those who eagerly await Him. That begs the question: who are these?!? Romans 8 tells us who those who “eagerly await” are: they are those who mourn their fallen condition, their sinful flesh! 
“And not only this, but also we ourselves, having the first fruits of the Spirit, even we ourselves groan within ourselves, waiting eagerly for our adoption as sons, the redemption of our body.” (Romans‬ ‭8:23‬)
Those who “eagerly await” Him, for whom He will return without reference to sin, are those who groan in their unredeemed bodies. I want to preserve such a groaning every single day, and temptation affords me a precious reminder. I want to hate it. I want to mourn like Jesus mourned, eagerly awaiting my deliverance from this body which can even be tempted to sin.