(in a good way), means,

To make efforts; to labor hard; to exert the powers of the body or mind earnestly; try hard to win.

To Strive
(in a bad way), means,

to quarrel; to dispute; to fight.

Strive to enter in at the strait gate: for many, I say unto you, will seek to enter in, and shall not be able.
Luke 13:24

...And the servant of the Lord must not strive; but be gentle unto all men, apt to teach, patient...
2 Timothy 2:24