When will the Old Testament saints be raised? Will their blessings be earthly or heavenly?

This text is from a transcript of a question-and-answer session with David Gooding.

The answer to the first part of the question seems to me to be given in that Scripture that says, 'they that are Christ's at his coming' (1 Corinthians 15:23). Galatians 3:29 tells me that, as a believer in Christ, I am the seed of Abraham: 'If you are Christ's, then are you Abraham's seed, and heirs according to the promise'. And so, 'they that are Christ's [shall be raised] at his coming'.

To answer the second part of the question, I would refer to Hebrews 11. This is talking about the Old Testament saints:

These all died in faith, not having received the promises, but having seen them afar off, and were persuaded of them, and embraced them, and confessed that they were strangers and pilgrims on the earth. For they that say such things declare plainly that they seek a country. If indeed, they had been mindful of that country from whence they came out, they might have had opportunity to return. However, now they desire a better country, that is, an heavenly. (Hebrews 11:13–16)

That is telling us that Abraham, Isaac and Jacob and the saints of the Old Testament—Abraham and company in particular—who left their fatherland on earth and became pilgrims, did so because they were seeking a heavenly fatherland. Therefore, I presume that their blessing will be heavenly. God is not ashamed, says Scripture, to be called their God. 'He has prepared for them a city.' He will not disappoint their expectation, which is to have a heavenly fatherland.