When understanding Scripture, context is extremely important. So is the chronology of events. Usually, there are simple explanations regarding the supposed contradictions in the Bible.
If the devil can get you to question the authority of the word of God, then he has you.
John 2:13-17 talks about the cleansing of the temple. Everywhere Jesus went, he wasn’t happy-go-lucky. Sometimes he got angry because of peoples’ unrighteousness.
Because this event occurs in John 2, it implies it happened near the beginning of Jesus’ ministry. Matthew 21 refers to this event much later. That’s because there were two separate accounts of Jesus cleansing the temple. One occurred near the beginning of His ministry, the other occurred near the end. (One mentions the use of a whip, one does not.)
John 6:5-13 records the feeding of the multitude. There were 5,000 men, 5 loaves and two fish. There were 12 baskets of food left over. Mark 8 says there were 4,000 men, 7 loaves and a few small fishes. There were 7 baskets left over. Again, these are not contradictory descriptions of the same event, but two separate events. Mark 8:19-21 clarifies this.
God’s people understand the things in Scripture. Lost people do not understand.
2 Samuel 6 — How many children did Michal have?
In verse 23, we are told that Michal, daughter of Saul, had no children until the day of her death. But in 2 Samuel 21:8, we are told she had 5 sons. However, she brought them up for Adriel. Her five sons were adopted. She had borne no children of her own.
That non-believers cite these things as contradictions illustrates their desire to falsely cast doubt on the word of God. But the Bible clearly explains itself.
Matthew 24 — This generation shall not pass?
Verses 32-35 (red letters), known as the Olivet discourse, explain that this generation shall not pass until all these things are fulfilled. Some scholars believe this is a copyist’s error. (Of course, a God big enough to inspire the Bible is big enough to preserve it.) Matthew 24 is prophesying the coming tribulation. Thus the generation of which He speaks is not the generation that existed then, but the generation yet to come.
Furthermore, the generation of which He speaks is the Jewish nation. It will not pass away until God wills it. One day, we will all be in the family of God. He is still working with the Jewish people today.
Revelation 8 — Grass or no grass?
In verse 7, there is a cataclysm that incinerates one-third of the trees and all the green grass on the earth.
But Revelation 9:3-5 foretells a later cataclysm in which locusts come to destroy, but are told not to hurt the grass. This plague lasts 5 months. There is also a year between these two judgments. Clearly, grass grows back during this period.
Sadly, there are people willing to go to Hell over this nonsense. Again, the devil would create doubt over the word of God regarding contradictions that don’t actually exist.