Because most people say so. But Jesus said, “wide is the gate and broad is the road that leads to destruction, and many enter through it…small is the gate and narrow the road that leads to life, and only a few find it” (Matthew 7:13-14).
Because my religious tradition says so. But Jesus said some religious people “nullify the word of God for the sake of their tradition” (Matthew 15:6).
Because the preacher says so. But John said we should “not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world” (1 John 4:1).
Because my heart says so. But Jeremiah said, “The heart is deceitful above all things” (Jeremiah 17:9).
What’s left? How about because the Bible says so? Paul said, “All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the man of God may be thoroughly equipped for every good work” (2 Timothy 3:16-17). That seems pretty simple.
What makes you say so? We answer “the Bible only.”