Paul speaks here of having strong faith as if a person were standing, instead of falling. AT: "to make your faith strong" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Paul says that God has revealed previously hidden truths to the believers. He speaks of these truths as if they were a secret. You can translate this in an active form. AT: "because God has revealed to us believers the secret that he was keeping for a long time" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-activepassive]])
The verbs "revealed" and "made known" mean basically the same thing. Paul uses both of them to emphasize his point. You can combine these words and translate this in an active form. AT: "but now the eternal God has made it known to all the nations through the prophetic writings" (See: [[rc://en/ta/man/translate/figs-doublet]] and [[rc://en/ta/man/translate/figs-activepassive]])
# for the obedience of faith
Here "obedience" and "faith" are abstract nouns. You can use the verbs "obey" and "trust" in your translation. AT: "so that all nations will obey God because they trust in him" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])