What Does It Mean To "Believe"?

They replied, “Believe in the Lord Jesus, and you will be saved—you and your household.” (Acts 16:31)
“Believe in the One He has sent.
What does it mean to “believe in the Lord Jesus”?
What started me thinking were Jesus’ words in the sixth chapter of John: “The work of God is this: to believe in the one he has sent.”
“Do not work for food that spoils, but for food that endures to eternal life, which the Son of Man will give you. For on him God the Father has placed his seal of approval.” (John 6:27)
The people following the Lord desired to know what to do.
Then Jesus presented to them a concept that appears several times in the sixth chapter of John:
“Food that endures to eternal life.”
This could mean that when we read or hear the Lord Jesus, and believe what we read, it is as food to us. And this probably is true. But I think it means much more than this.
Notice:
“Whoever eats my flesh and drinks my blood has eternal life, and I will raise them up at the last day.” (John 6:54)
The Jews listening to Him understood that Jesus was speaking of eating His flesh and drinking His blood, not just of believing what He was saying. Being Jews, they were offended at the thought of eating Christ’s flesh and drinking His blood. The Law forbids the drinking of blood.
Since the Body and Blood of God’s Lamb is still being distributed today, it must be true that God blesses and increases the Body and Blood of the Lord Jesus just as was true of the loaves and fish.