In giving the requirements for who can make the offerings among the Levites, the Lord says:
Leviticus 21:17-23
17 Speak unto Aaron, saying, Whosoever he be of thy seed in their generations that hath any blemish, let him not approach to offer the bread of his God.
18 For whatsoever man he be that hath a blemish, he shall not approach: a blind man, or a lame, or he that hath a flat nose, or any thing superfluous,
19 Or a man that is brokenfooted, or brokenhanded,
20 Or crookbackt, or a dwarf, or that hath a blemish in his eye, or be scurvy, or scabbed, or hath his stones broken;
21 No man that hath a blemish of the seed of Aaron the priest shall come nigh to offer the offerings of the Lord made by fire: he hath a blemish; he shall not come nigh to offer the bread of his God.
22 He shall eat the bread of his God, both of the most holy, and of the holy.
23 Only he shall not go in unto the vail, nor come nigh unto the altar, because he hath a blemish; that he profane not my sanctuaries: for I the Lord do sanctify them.
Above taught that all those who made the offerings - anyone could eat them (verse 22) - must be without physical blemishes, including deformities. Why?
The reason why the one making the offerings had to be without blemish is the same reason why the Passover lamb explicitly had to be without blemish (Exodus 12:5), and why many other sacrifices had to be without blemish as well (Exodus 29:1, Leviticus 1:3, 1:10, 3:1, 3:6, 4:3, 4:23, 4:28, etc., etc.).
All of these things pictured the sinless Jesus Christ (2 Corinthians 5:21, Hebrews 4:15: 1 Peter 2:21-22: 1 John 3:5), and so having something with a blemish or defect serve as that symbol would be inappropriate.
In our modern, psychotic culture, this is anathema. Everyone must be identical, and be told that they can do anything. So, it's no wonder this passage is hated - it demonstrates that life isn't fair, and if you've been born a certain way, there are things you cannot do, and should not try to do. God has other plans for your life, and if that doesn't include being a model, or athlete, or talk show host, it's only immaturity and entitlement that would cause someone to throw a fit.
Everyone has strengths and weaknesses, unique to them. Looking at someone else with envy because they are performing a role that you cannot is rebellion against God, who made you, and gave you strengths and weaknesses unique to you, and has different expectations for you based on those strengths and weaknesses (2 Corinthians 8:12, Luke 12:48).
This passage has absolutely nothing to do with a disabled person's ability to have a relationship with God, which is how it is usually misconstrued by Atheists who hate God and the Bible. It was a rule for the Levites, and gave criteria for a certain role in the ceremony of offerings under the Old Covenant.
The implications of this passage are that God has different roles for different people. Recognizing this fact grounds a person in reality, rather than patronizing them with lies. This passage serves as a fantastic example of how a Biblical worldview runs completely contrary to our modern, absurd culture, which is intent on denying reality in a whole host of ways.