Summary: Death is not the end.
AN ESSENTIAL ARTICLE OF THE CHRISTIAN FAITH
The Sadducees, the ruling class in the Jerusalem Temple, flatly denied the resurrection of the body (Luke 20:27). They failed to find this teaching in their only authoritative Scriptures, the five books of Moses (Genesis to Deuteronomy). To them it seemed to belong to relatively ‘recent’ books such as Daniel (cf. Daniel 12:2).
The Pharisees, on the other hand, believed and taught this doctrine. This is why they congratulated Jesus on His ingenious response (Luke 20:37-39). According to Moses, argued Jesus, death is not the end because Abraham, Isaac and Jacob are still alive to God (cf. Exodus 3:6)!
When the Apostle Paul, a former Pharisee now converted to the Christian faith, was obliged to make his defense before the Sanhedrin - the council made up of both Sadducees and Pharisees - he cried out: ‘it is of the hope and resurrection of the dead that I am held to account’ (Acts 23:6). Later the Apostle would declare the vanity of a ‘faith’ which denies the resurrection (1 Corinthians 15:14; 1 Corinthians 15:17). We gather from all this that belief in the resurrection of the body is an essential article of the Christian faith.
As to the nature of the resurrection, Jesus does give some clues. The Sadducees were ridiculing belief in the resurrection when they asked their hypothetical question (Luke 20:28-33), based on their own favoured Scriptures (especially Deuteronomy 25:5). In the wording of this argument they were playing the part of unbelievers!
You are confusing “this age” with “that age”, suggested Jesus (Luke 20:34-35). For those accounted worthy to obtain that age and “the resurrection which is from among the dead” there will be no more marrying and being given in marriage. This is not a call to celibacy in this life, but a recognition of the ‘change’ which will occur at the resurrection (cf. 1 Corinthians 15:51-54).
“Neither can they die any more, continues Jesus” (Luke 20:36). In this, they will be “like the angels” – immortal. The proof of their new status as “the sons of God” (cf. Job 38:7) will be that they are “sons of the resurrection” (cf. Romans 8:21; Romans 8:23).
This connects with the idea that even Jesus was ‘proclaimed to be the Son of God with power… by the resurrection from the dead’ (Romans 1:4). If we want some idea of what the resurrection body may be like, we have only to look at that of the risen Lord Jesus, which had marks of both continuity and discontinuity with His earthly body. ‘And if Christ rose from the dead’, argued Paul in the homily already referred to, ‘how can anyone say that there is no resurrection?’ (1 Corinthians 15:12).