God Bless You!
 
People may say, "God bless you!" when you sneeze. They may say it as a way of saying goodbye.
 
Some believers find it offensive for they see it as telling God who he can and cannot bless. Others say it is only asking God to bless. However, believers who think that God predestined some people to enjoy happiness forever and destines the rest to endure everlasting torment in Hell should find it offensive.
 
It is doubtful that a knowledgeable Catholic could say it. After all it is only ordained clergy that can give a blessing.
 
The downside of that practice is as follows.
 
It will be said to a person who is not religious.
 
It will be said to a person who is angry at God and doesn't want to hear God being mentioned.
 
It will be said to a person who is not living as a religion's God says he or she should. Suppose it is true that living together before marriage is really a grave sin as the Church teaches. Then it follows that if you bless the couple you are saying, "The way you are living is a curse upon you. May God split you up if necessary to get you to do right. This splitting then would be a blessing." The blessing is a silent curse in a sense. But a real curse all the same. It's an expression of intolerance. It's: "I know better than you. If I had the power to do it, you would do my will."
 
The concept of God is offensive to many humanists and atheists. It implies guilt by association. The Christians are colluding with a God who lets the innocent suffer unimaginably. We don't guess that a wife beater is doing what is right under the circumstances. Yet we guess that God is when he does worse - eg, who made the AIDS Virus?
 
To say "God bless you!" implies, "May you get addicted to God." It is evil and intolerant.
 
The concept of blessing is offensive. It says that it is up to God to bless me. No. It is up to me to bless me by accepting the unpleasant things in life and having a good attitude in general.
 
The saying is promoting the idea of God. It's a form of proselytism.
 
The Christian would not like it if somebody said, "May Krishna or Buddha or Venus bless you."
 
The Bible says that gods besides the Christian God are demons. Christians who say "God bless you" are not respecting Muslim sects or pagans who may consider their god to be a vindictive jealous entity.
 
It is never necessary to say, "God bless you." Something else would do. It is more important to be offered help from a person than it is to hear them ask God to help you. Saying something neutral would be better. For religion to oppose such neutrality is it submitting to silent sectarianism - the kind that always erupts in anger and blood.
 
How to respond?
 
Many of those who use the blessing mean well.
 
Say, "Thanks for your goodwill. I'm not really into religion though." This does not express approval for what was said but approval for the goodwill intended by it. Creating awareness of the existence of unbelievers helps people see and feel that unbelief may be an option for them. It may make them investigate why not everybody needs or wants to be in a religion.
 
Many knowledgeable believers do mean it in the offensive sense.
 
Believers think that God represents the notion that you must act to benefit others even at your own loss and that it is moral and acceptable for others to accept the benefit you give. The divine blessing is really a grace to make you put others before yourself and treat yourself as an inferior. God is not a blessing.
 
Believers in God's blessing have argued, "Let us oppress or neglect the poor for God will reward them or make it up to them on earth or in Heaven or both." If their argument is wrong, it has some merit and truth if there is a God. For the atheist, it deserves total opposition. For the believer, there is some good in it. That alone proves that belief in God is not good or a blessing. The blessings happen because human goodness outs in spite of the poisonous belief in God.
 
Conclusion: If believers want to say "God bless you!" let them be sure that they only say it to one another if they are sure the blessing will be welcomed.