Synoptics - or Synoptics Gospels - Matthew, Mark, and Luke are "seen together" because they share the same-but-different content.
It is always best to see two versions of the same material. Mark can be very short but also more detailed and lengthy.
Each Gospel has its own character as books and also harmony with the other two.
The apostates (academics who no longer believe the Scriptures) are known to invent new theories that reject the divinity of Christ, the Trinity, faith in Christ, and anything that irritates their very sensitive thoughts. Most universities, even community colleges have religion departments where only atheists can teach - even part-time. Those with tenure are quite outspoken. Seminaries and denominational colleges are rife with rationalism and a "higher level of understanding."
John's Gospel is quite different and was clearly written to share the perspective of the "disciple Jesus loved." Yes, the apostates deny that too - and place John's Gospel at 300 years later.
