Persistence

no matter what happens

I'll be there for you, come rain or come shine, supporting you through thick and thin.

up to the point where something faces its inevitable failure or fails to achieve any degree of success

He vowed that he would keep fighting until the bitter end.

to keep on trying despite the high chance of failure

They beat us in the end, but we went down swinging.

to manage to stay strong and determined, despite the likelihood of failure

For years they struggled to keep their heads above water.

to survive a tough situation or disastrous experience and get the chance to try again

I never thought I’d live to see the day when children could take their own parents to court!

to persist on achieving a particular result by taking risks, particularly when one should stop

You're always pushing it and you take stupid risks!

to try one's best to stay strong and determined in the face of danger or extremely low odds of success

She and her campaign put up a fight to the very end, but it was clear in the weeks leading up to the election that she would lose.

to keep defending one's plans or opinions despite facing opposition

Clare stood her ground in the meeting and refused to be intimidated even when Michael got angry.

by any means that is necessary

He was determined to make it to the top of the mountain by hook or by crook, no matter how difficult the climb.

no matter how many obstacles one might face or how hard achieving something gets

He confirmed that, come hell or high water, he will make his first trip to Scotland in November.

no matter what happens or how difficult thigs turn out to be

They're going to make the change, come what may.

no matter how many problems one might face or how hard achieving something gets

I was battling my way along the promenade in the teeth of a force ten gale.

an option or solution that is only chosen when every other alternative has failed

He used his savings as a last resort to pay the bills.

firmly determined and focused on the task at hand

Martha's dead set on having a new bike.Ethan is dead set on being an actor.

to maintain a good performance and continue persevering in one's efforts

Keep it up champ!Only one more round to go.

to be very serious about fulfilling one's intentions

When the CEO walked into the room, everyone knew she meant business and was ready to make tough decisions.