I should start by saying Atheism is one of those other religions. The dichotomy Atheists seek to present between themselves, and all others whom they call “religious,” is a false one.
The Christian response to other religious claims, is not to suggest that a person read about them all, refuting them one by one. Rather, the Christian looks to God’s word (Romans 10:17) and the Holy Spirit (John 15:26) for the surety of their faith. In other words, the Christian knows Christianity is true, (and the other religions are false), through spiritually seeking God. Jesus said, “It is the Spirit who gives life; the flesh profits nothing. The words that I speak to you are spirit, and they are life” (John 6:63). “But the natural man does not receive the things of the Spirit of God, for they are foolishness to him; nor can he know them, because they are spiritually discerned” (1 Corinthians 2:14).