Religion is when one holds to a system of beliefs. These beliefs can be sterile and emotionless. On the other hand, a relationship is when two or more parties are mutually interacting. The difference between the two concepts is that religion is only one sided, while a relationship involves all participants. This is why a personal relationship with Christ is more important than mere Christian religion.
It is quite possible for a person to subscribe to a set of Christian beliefs and not truly know the founder of that religious movement. If a person practices the principles of Christianity then that person will have many desirable qualities that others will see. For example, that person would show compassion, give to the needy, obey the laws of the land, care for their own family, and be a generally good person. This could all be done by simply following a set of religious standards. This is religion, not a relationship with Christ.
A relationship with Christ must first be founded upon a sincere belief that he is real and is capable of having a relationship with us. This does not take the same form or pattern that we see with relationships in the human realm. There are similarities to be sure, but, it is not exactly the same. A true relationship with Christ produces outward evidence that is shown by compassion, patience, giving to the needy, caring for your own family, and being a good person, to name a few. Religion can be practiced without being personal. A relationship, by its definition, assumes that those involved are relating to one another. Any relationship that loses its personal elements does not continue very long. We become distanced and then that relationship eventually dies.
Here are some things that are involved with a relationship that cannot take place the same way in a religion:
1. Two way communication. This happens on our part through prayer and on Christ's part by answers to prayer and enlightenment through the scriptures.
2. Struggles in the relationship. This happens when we have doubts and emotions from the relationship.
3. Reconciliation. This happens on the part of the one who was offended. It is called forgiveness and Christ forgives us for our offenses, we have not been offended by him.
Religion allows us to keep away from personal feelings while telling ourselves we are good with God because of our own efforts. It is better to be in a relationship with Christ who sees past our best efforts and loves us anyway.