The word 'only' is striking — pride is the exclusive root of contention. Arguments, conflicts, and strife are ultimately pride problems: someone insisting on being right, refusing to yield, or unwilling to submit. The remedy is the opposite of pride: being 'well-advised' — willing to listen, seek counsel, and receive wisdom from others.
Memory phrase: Pride starts every fight.
Talk about it: Has pride ever started a fight or argument? What happened?
Prayer: God, keep pride out of my heart.