I think the title says it all, but please do not be crude or ignorant and more importantly, vague. State what you think and back it up.
To be vague, Religion can be both, but relationship with Christ is better
Dee, let's face facts.
Religion (n): "Submission to a code of belief that may or may not have a basis in fact, however intensely the believers may assent to that doctrine . . .." (Religare': "to set oneself below, or aside, from any reasonable course of conduct."
Atheism fits that definition to the letter.
Faith (adv): "A relationship of trust based on agreement and intuition, where a person is convinced of the good will and adherence of another to a set agreement." (Fate [past-perfect tense]).
That is why Christians do not have religion. We never have. We never will.
"By faith, you are saved through grace, and that not of yourselves. It is the gift of God, not of works, lest anyone should boast, for we are His workmanship, appointed to good works through Jesus Christ . . .." Ephesians 2:8--10.
Atheists have religion. Christians have faith. There is no point in common between the two.