You have judged rightly according to the Scriptures, and it is needful to speak the truth plainly though tenderly where sentiment would mislead.
There is a common and well meaning speech at the graveside, that the departed are together again, as if death itself were a reunion. But our Lord has taught us otherwise. I say unto you, That many shall come from the east and west, and shall sit down with Abraham, and Isaac, and Jacob, in the kingdom of heaven, but the children of the kingdom shall be cast out into outer darkness, there shall be weeping and gnashing of teeth. Heaven is not opened by death, nor by the affection of a marriage bond, but by grace through faith in Christ. There should be as much difference between the worldling and the Christian as between Hell and Heaven, between destruction and eternal life.
The only true reunion after death is in Christ. The Scripture speaks of the whole family in Heaven and earth, not two families nor a divided family, but one family gathered together in one, all things in Christ, both which are in Heaven and which are on earth. Those who are in Christ, whether they have fallen asleep or remain, are fellow citizens, and neither death nor Hell can erase a single name, for our citizenship is in Heaven. There we shall meet, and there we shall be happy for ever, but only because we have first been made one in Him.
If both are without Christ, there is no comfort in the thought of meeting in Hell. Hell is outer darkness, not a place of fellowship or love, and those cast there are not together in any blessed sense. If one is saved and the other is not, they go in different directions, as you have said, for what fellowship hath light with darkness. Heaven must be in us before we can be in Heaven, and being born from above we are the same persons that will be in Heaven. Without that new birth there is no entrance, though the grief of survivors may wish it otherwise.
And even for those who are both saved, we must not think of Heaven as a mere continuance of earthly marriage. In Heaven they are as the angels, yet they are truly one family, knowing and loving each other in a purer way than before, sitting down together in the kingdom with Abraham and Isaac and Jacob. It is a true Heaven, with a true Christ, in true glory, and only those who know the Truth of His salvation shall dwell there.
That salvation is wholly of the Lord. It was His in the planning, His in the procuring by the precious blood of Christ, and His in the applying by the Spirit. Nothing whatsoever that man does can avail him towards his own salvation, but when a man comes in very deed to a knowledge of the truth, that man lost and Christ his Savior, he trusts Christ and he is there and then saved from the guilt of sin. The Word saith, Look unto me, and be ye saved, for beside Him there is none else. You who have really transgressed, you are the men and women for whom there is truth in God's salvation, but if there is no truth in your sinnership, there is to you no truth in Christ's salvation. There must be a real atonement believed and received.
Therefore let this correction lead not to coldness but to earnestness. While there is breath, there is hope. Let us plead with the living, that they may be comforted with true comfort, for this is our comfort in affliction, that His Word hath quickened us. Let us pray that the Lord would comfort hearts and establish them in every good word and work, and that many yet from east and west may come and sit down in the kingdom, that what death has divided for a season may be gathered in Christ for eternity.