It's a matter of fact that you'll lose in the short term, but it'll come at an advantage in the long run. Don't focus on immediate losses but instead the guarantee of future profits.
ご質問ありがとうございます。
「損して得取れ」は英語で「gain can come at a loss」と言えます。
また、「一時的にはむしろ損を覚悟し、長い目でみて得を取れ。目前の損失は度外視して、将来の利益を確保せよ。」と説明したいなら、英語で「It's a matter of fact that you'll lose in the short term, but it'll come at an advantage in the long run. Don't focus on immediate losses but instead the guarantee of future profits.」という風に言えます。
ご参考になれば幸いです。
アメリカ合衆国 
