our A: There are many Christian denominations and churches: Catholic, Presbyterian, Methodist, Baptist, Lutheran, and so on. Being a member of one doesn't determine whether a person is a Christian.
The real issue is whether the person individually has Jesus Christ living inside of him or her...if they actually have a personal relationship with God.
In the Gospel of John, we are told, "to all who received him [referring to Jesus], to those who believed in his name, he gave the right to become children of God."1 Why do we have to become children of God? Because until then, God is distant. We may know he's there. We may know we are supposed to worship him. We may even know that in times of need, he's the one to pray to. But there is a distance we are aware of, and it is because of our sin.
Now, as long as we live and breathe, guess what, we're going to sin. We're going to do things our way instead of God's way. But our sin need not remain a barrier between us and God. Here's how.
The Bible says that there is a penalty for sin, and it might be greater than you'd expect. The penalty for sin is death. It's not just the penalty for sins like murder. It's God's judgment against any and all sins. The Bible says, "For the wages of sin is death..."2 So that we would not have to die eternally separated from God because of our sin, Jesus died in our place. He fully paid for our sin. And offers us complete forgiveness. Not temporary forgiveness. Even for the sins we will commit in the future, we can have his forgiveness now, because Jesus died for all of our sin. We can immediately begin a close, personal relationship with him, that barrier of sin being gone. It isn't that we become perfect and no longer sin. But we become forgiven when we see that Jesus died for our sin, in our place.
"Yet now God in his gracious kindness declares us not guilty. He has done this through Christ Jesus, who has freed us by taking away our sins. For God sent Jesus to take the punishment for our sins and to satisfy God's anger against us. We are made right with God when we believe that Jesus shed his blood, sacrificing his life for us."3
When we receive Jesus Christ into our lives, God declares us "not guilty" and he says that we are now "made right with God." Our relationship with God has begun in a real way, where we no longer know God is "out there," but instead we know that he lives inside of us. We have God's forgiveness, a relationship with him. "For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord."4
If you would like to be certain that you have a personal relationship with God, your sins forgiven, and no longer any barrier between you and God, the following explain how to have this now: Knowing God Personally.
(1) John 1:12
(2) Romans 6:23
(3) Romans 3:23,24 (NLT)
(4) Romans 6:23