Yes, but that doesn't answer the question, which was "If God chose Christians before the foundation of the world, how could Christians choose Him first, as you wrote?" If you say that God chose those who He foresaw would believe, then that takes the initiative in salvation from God, and leaves it to the sinner. Yet we are told:
“But God, who is rich in mercy, because of His great love with which He loved us, even when we were dead in trespasses, made us alive together with Christ (by grace you have been saved), and raised us up together, and made us sit together in the heavenly places]in Christ Jesus, that in the ages to come He might show the exceeding riches of His grace in His kindness toward us in Christ Jesus. For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast. For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand that we should walk in them.” (Eph 2:4-10 NKJV)
Notice those words, "lest anyone should boast." The whole passage attributes salvation from beginning to end to God. No idea there that the sinner, dead in trespasses and sins, has the ability to repent and believe on the Lord Jesus Christ, and that the sinners who exercise that ability who God chose to save.