「if it were not for ～」は「～がなかったら」という意味で、現在の事実の反対を表す仮定法の慣用表現です。
文法についてもっと理解を深めたい方は
英語検定に挑戦！「if it were not for ～・if it had not been for ～」をご覧ください。
If it were not for your help, I should fail.
もし君の援助がなければ、僕は失敗するだろう。
If it were not for earthquakes, Japan would be more comfortable to live in.
地震がなければ日本はもっと住みよい所なのだが。
If it were not for water, no living thing could exist.
水がなければ、どんな生物も生きられないだろう。
If it were not for your quick play, our team would not win.
君の機敏なプレーがなければ、うちのチームは勝てないだろう。
If it were not for your illness, I would take you to the party.
あなたが病気でなければパーティーに連れて行くのだが。
If it were not for air, we could not live.
もし空気がなければ、私たちは生きていくことができないだろう。
If it were not for your advice, my project would fail.
あなたの助言がなければ、私の計画は失敗するでしょう。
If it were not for approriate software, a computer would be a mere box.
利用できるソフトウェアがなければ、コンピューターはただの箱だ。
If it were not for music, life would be boring.
もし音楽がなかったら、人生は退屈だろう。
If it were not for the sun, nothing could live.
もし太陽がなければ、何も生きられないだろう。
If it were not for his idleness, he would be a nice fellow.
彼は怠け癖がなければ良い人なのだが。