Hebrews 9:28 is generally one of the first verses offered as proof there is to be a yet future return of Jesus. Let us notice a few things about the text.
The inspired writer says in verse 26 Jesus had appeared "once" to put away sin by sacrificing himself. The Greek word translated once is "hapax" and normally means "once for all time," see Jude 3, I Peter 3:18. The writer then says Jesus "shall appear the second time unto salvation," vs. 28.
The force of the word "second" as used here is the same as "once;" Christ would not appear again and again.
Almost all interpreters admit Jesus came in the destruction of Jerusalem. One writer commenting on Matthew 24:29-31 says "It is a coming of Christ in judgment upon the city of Jerusalem." But we ask, for what purpose did Jesus come in 70? It was not simply for judgment of the wicked.
In Luke 21 Jesus spoke of Jerusalem’s coming destruction: "then shall they see the Son of Man coming in a cloud with power and great glory" vs. 27. He said "when these things come to pass then look up and lift up your heads; for your redemption draweth nigh" vs. 28. In verse 32 he said it would be in that generation.
The word "redemption" used here is the identical word used in Romans 3:24; 8:23; I Corinthians 1:30; Ephesians 1:7,14, etc. to speak of the redemption of salvation.
With these few facts before us let us draw a conclusion.
Hebrews 9:28 says Jesus would appear a second time, not many times, unto salvation. Jesus said he was going to return at the destruction of Jerusalem and this would be the redemption (salvation) of his Body. He said it would be in that generation. Therefore Jesus’ return in the destruction of Jerusalem, for the purpose of redemption, is the return of Hebrews 9:28.
Since Christ’s coming in 70 was the coming for redemption, and since he was to return only once for salvation per Hebrews 9:28, then Christ’s return in 70 was the final coming of Christ.
This conclusion is corroborated in Hebrews 10:33-39. The writer addresses Christ’s coming in judgment and salvation: "For yet in a very little while, the Coming One will come and he will not delay." (Tragically, most commentators insist he has delayed.)
In the margin of your Bible, beside Hebrews 9:28, write Luke 21:28 and Hebrews 10:33-39. These verses give divine commentary on Hebrews 9:28.
Upon what basis can anyone postulate a future coming of Christ? He promised to come (once) again for salvation. He said when it would be; and he kept his word. It is something to ponder.