Please explain to me the translation to English “....за то, что....”.
I respect him for telling the truth in any situation. Я уважаю его за то, что он всегда говорит правду.

Here you use a simple sentence with the gerund as an object. There is no verbal form in Russian similar to the English gerund. To render its meaning we can use nouns, other verbals or clauses. “он всегда говорит правду” is an object clause. It is introdused to the main clause ending with the demonstrative pronoun “то” by the conjunction "что".