Only God knows who is saved and therefore who will sit next to him in the next life. No human knows.
Proclaiming it out loud is the heighth of arrogance; pride comes before the fall.
1st Cor 1: 30-31
“By His doing you are in Christ Jesus, who became to us wisdom from God, and righteousness and sanctification, and redemption, so that, just as it is written, ‘Let him who boasts, boast in the Lord’”
Psalm 35:2-3
My soul makes its boast in the Lord; let the humble hear and be glad. Oh, magnify the Lord with me, and let us exalt His name together!
If a believer finds himself frustrated by other believers who rejoice in their salvation, it is an indication that he is out of fellowship. Hebrews is an outstanding study regarding our eternal security and how God provides a system of check and balances in our conscience which are manifest when we backslide. One of our first disciplines when we backslide is lack of joy. Frustration is a symptom of thinking independent of Him, when we are confronted with reality that isn't consistent with our thinking independent of Him.
The Cosmic system is a system of good and evil which seeks to produce a counterfeit paradise independent of God. The cosmic system (COSMOS(Greek) = WORLD(English) defn = making order out of disorder) begins in our thinking. When we think independent of God (sin) we are tempted to place our hope in ourselves rather than in Him. On the contrary, when we initially place faith in Him, our first hope is realized when the Holy SPirit makes our faith efficiacious for salvation. There is a joy associated with our rest in Him.
The person who fails to realize their first hope in their salvation may be tempted to place their hope in a counterfeit system of thinking and or works to satisfy their hope. Such is a misplaced hope because only He is eternally trustworthy, worthy of faith. Nevertheless, to the backsliden believer, we might become frustrated that other believers are not sharing the same misery the backsliden believer might experience.
The starting place for this malady is the same for every problem a believer will ever face in eternal life, namely, first we place a simple faith in God on His grounds and let Him handle the situation. We might also natrally sacrifice the old man, the natural man, by simply returning to God and placing anything known or unknown which was independent of Him, back into His hands. By faith we simply rest and allow Him to do all the work.
A consequent of the new life is a freshness through faith in Him.
I rejoice in my salvation through faith in Him, in the hope He has made real, and in the new hope He provides by my remaining in fellowship with Him allowing Him to further sanctify my thinking so that I might be more prepared to be in the right time and place equipped with the armamnet to perform work per His will,..that I might be an agent in His plan, which might mean even being an invisible warrior not known to any other person in the performance of His will. It is all in His hands at all times. Thank you Lord!