People can only give when they see God as generous. If a preacher proclaims God as stingy with his time, mercy and grace people’s giving of themselves will dry up as well.
*Unspeakable (anekdiēgētō) is only used here in the whole New Testament and it means that the gift of Christ is incapable of being adequately expressed, unutterable and ineffable. Christ is the Gift who is so celestial and sacred he is beyond words. It occurs nowhere else in the New Testament.
It is higher than the mind can conceive; higher than language can express…Man had no claim on God. He could not compel him to provide a plan of salvation; and the whole arrangement – the selection of the Savior, the sending him into the world, and all the benefits resulting from his work, are all an undeserved gift to man. (Barnes).
“Our thankfulness should be shown by highly prizing and valuing this gift; by laying the whole stress of our salvation on Christ…” (Gill)
Here is a short synopsis by Alexander MacLaren
There is one blazing sun which shines out in the midst all the galaxies which fill the heavens. There is one gift of God which is beyond all others and only deserves the designation of “unspeakable.” The gift of Christ attracts all other divine gifts after it. “How should He not with Him also freely give us all things.” The expression here “unspeakable” is what I wish chiefly to fix upon now. It means literally that which cannot be fully declared. Language fails because thought fails.
The love is the cause of the gift and the gift is the expression of the love. John’s Gospel says that the Son which is in the bosom of the Father has declared Him. Paul here uses a related word for “unspeakable” which might be rendered, “that which cannot be fully declared.” The declaration of the Father is that He declared the undeclarable…language fails when it is applied to the expression of human emotion…with lowly condescension He uses all sweet images drawn from earthly relationships, to help us in understanding His love—the love of father, mother, husband, wife, brother, friend, and after…<yet> all are exhausted…
When Paul in the Epistle to the Romans says, “He that spared not His own Son but delivered Him up for us all” he is…quoting, the divine words to Abraham, “Seeing thou hast not withheld thy son, thine only son, from Me” <This> permits us to parallel what God did when He sent His Son with what Abraham did when, with wrung heart…he bound and laid Isaac on the altar and stretched forth his hand with the knife in it to slay him. Such a representation contradicts the vulgar conceptions of a passionless, self-sufficing, icy deity… All through His life Christ was in contact with evil, and for Him the contact was like that of a naked hand pressed upon hot iron. The sins and woes of the world made His path through it like that of bare feet on sharp rocks. If He had never died it would still have been true that, “He was wounded for our transgressions and bruised for our iniquities.” On the Cross, He completed pouring out his love which had continued pouring throughout His life and “poured out His soul unto death” as He had been pouring it out all through His life. We have no measure by which we can estimate the inevitable sufferings in such a world as ours of such a spirit as Christ’s…Should it not call forth from us floods of praise and thanks to God for His unspeakable gift?
In Christ are hid, “all the treasures of wisdom and knowledge.” When God gave us Him, He gave us a storehouse in which is contained treasures of truth which can never be fully comprehended, and which, even if comprehended, can never be exhausted. The mystery of the Divine Name revealed in Jesus, the mystery of His person, are themes on which the Christian world has been nourished ever since, and which are as full of food, not for the understanding only, but far more for the heart and the will, to-day as ever they were. The world may think that it has left the teaching of Jesus behind, but in reality the teaching is far ahead…and the Gospel is the guide of the race, and each generation gathers something more from it…each of Christ’s scholars finds about gift, and in the measure of his faithfulness to what he has found makes ever new discoveries in the unsearchable riches of Christ. After all have fed full there still remain abundant baskets full to be taken up.
No single soul, and no multitude of souls, can exhaust Jesus; neither our individual experiences, nor the experiences of a believing world can fully realize the endless wealth laid up in Him. He is the Alpha and the Omega of all our speech, the first letter and the last of our alphabet, between which lie all the rest. Who has ever spoken adequately and in full correspondence with reality what it is to have God’s pardoning love flowing in upon the soul? Many singers have sung sweet psalms and hymns and spiritual songs on which generations of devout souls have fed, but none of them has spoken the deepest blessedness of a Christian life, or the calm raptures of communion with God. For us the only recompense that we can make for the unspeakable gift is to receive it with “thanks unto God” and the yielding up of our hearts to Him. God pours this love upon us freely…it is unspeakable in the depths of its source, in the manner of its manifestation, in the glory of its issues. It is like some great stream, rising in the trackless mountains, broad and deep, and leading on to a sunlit ocean…