What is the meaning of Matthew 19:27-30?

27 Then answered Peter and said unto him, Behold, we have forsaken all, and followed thee; what shall we have therefore? 28 And Jesus said unto them, Verily I say unto you, That ye which have followed me, in the regeneration when the Son of man shall sit in the throne of his glory, ye also shall sit upon twelve thrones, judging the twelve tribes of Israel.

29 And every one that hath forsaken houses, or brethren, or sisters, or father, or mother, or wife, or children, or lands, for my name’s sake, shall receive an hundredfold, and shall inherit everlasting life. 30 But many that are first shall be last; and the last shall be first. (Matthew 19:27-30 KJV)

William Burkitt New Testament

The apostles having heard our Saviour’s command to the young man to sell all and give to the poor, St. Peter in the name of the rest, tells Christ, that they had left all, and followed him;  Behold, we have left all.  

Where, Note, How Peter magnifies that little which he had left for Christ, and ushers it in with a note of observation and admiration also, Behold! We have forsaken all, what shall we have then?  

Learn thence, That although it be a very little that we suffer for Christ, and less that we have to forake upon his account, yet we are apt to magnify and extol it, as if it were some great matter, Lord, we have forsaken all. What all! His tattered fisher-boat, and ragged nets; scarce worthy to be mentioned: yet, how is it magnified! Behold! Lord, we have left all!  

But observe our Lord’s kind and gracious answer; “You that have left all to follow me, shall be no losers by me; for in the regeneration, that is, at the resurrection, when believers shall be perfectly renewed, both in soul and body, and shall enjoy my kingdom, then, as I sit upon the throne of my glory, so shall you sit with me in a higher degree of dignity and honour, judging the twelve tribes of Israel; that is, the Jews first, for their unbelief, and then all other despisers of gospel grace and mercy.”

Learn, 1. That such ministers as do most service for Christ, and forsake most to follow him, shall in his kingdom partake of most honour and dignity with him and from him.

2. That as the ministers of Christ in general, so his twelve apostles in particular, shall sit nearer the throne of Christ, and have an higher place in glory at the great day, than ordinary believers.

The foregoing promises, Mt 19:28, respected the apostles; this, all Christians, who forsake their dearest enjoyment for Christ: he assures them, they shall be recompenced in this life an hundred-fold: how? Non formaliter, sed endnenter: Not in specie, but in valour; not in kind, but in equivalence; not an hundred brethren or sisters, or lands, but first, He shall have that in God, which all creatures would not be to him, if they were multiplied an hundred times.  

Secondly, The gifts and graces, the comforts and consolations, of the Holy Spriit, shall be an hundred-fold better portion than anything we can part with for the sake of Christ and his gospel here. Though we may be losers for Christ, yet shall we never be losers by him. Christ gives present recompences, as well as future rewards; insomuch that they who have suffered and lost most for Christ, have never complained of their sufferings or losses.

Therefore never be afraid to lose anything for Christ, he will not only see you indemnified, but plentifully rewarded; in this world an hundred-fold; in that to come, life eternal.