Why did Abraham Lincoln revoke the right to Habeas Corupus?

Because it was a situation of 'civil war' where some officials, lawmen, even some judges and courts could not be trusted (they might work for the other side). The temporary suspension of a Habeas Corpus (the release of a jailed prisoner to be brought to a court just on 1 judges signature) was to guard against this. When used it was used mostly in the 'border states' of Kentucky, Tennessee, Missouri where the state populations were split between being for the North or the South and no one could be fully trusted not to free prisoners, free rebels, free pow's under the misuse of Habeas Corpus....it was temporarily suspended.

Secession had put Lincoln's political career and reputation in jeopardy - that's why he raised an army and sent it to invade the seceding states,so as to force them back into the Union.

Lincoln was willing to use whatever means were necessary to win the civil war - including riding roughshod over the Constitution.

He believed he needed every weapon he could use, including revoking sanctioned law.

He was probably right.

And there were spies everywhere working as agents for the Rebels.