Blessed are the pure in heart, for they shall see God
The promises of the first five beatitudes talk about being filled and comforted, meek and merciful, inheriting the earth, or being part of the Kingdom of Heaven. But, I think the promise of this beatitude is the greatest, because it is the promise of seeing God. To see the God, the same God who in exodus said "You cannot see my face, for no one may see me and live." But, through Jesus Christ, our longing for purity will lead us to the face of our Heavenly Father.
Seeing God, isn't that the goal of every Christian, isn't that what we are living for? That we may live our life in such a way that we see God. If we see God, that opens up all of His blessings, not only for the afterlife, but also for life here and now. The key to receive these blessings is living your life with a pure heart. Without a pure heart you cannot be poor in spirit. You cannot mourn for your sins without having a pure heart. You cannot be meek, or hunger and thirst for the righteousness of God. You can't be merciful, you can't be a peacemaker, or you can't withstand persecution for the name of Christ without a pure heart. The heart of the matter is the matter of the heart.
The first thing we can learn from this beatitude is that Jesus is concerned with our heart. Your heart is what you are in the private parts of your thoughts and feelings, when no one knows them but God. What you are in private matters to God as much as what you are in public. Jesus was not born into this world because we have some bad habits that need to be broken, He came into this world because we have hearts that need to be purified.
The second thing we can learn is that having a pure heart means living for the sole purpose of God, to have a heart that is fully devoted to God. If we live a life with a pure heart, a life that is pleasing and fully devoted to God, we will enjoy God's presence in our life right here in this world. As we walk in His ways, as we get to know Him through His word, as we trust Him through our prayers, our knowledge and experience of God will let us see Him present in our lives today. If we have this goal for our life, the outcome will be a daily walk with God that is pleasing to Him, and blesses us. This, fills our lives with joy until we can be called home and live with Him forever. Amen........