Other world religions acknowledge that the problem that stands between us and the divine is the problem of sin. Genesis 3 tells the story of sin and rebellion entering creation. The result is separation from our Heavenly Father forever (i.e. spiritual death). What can we do about it? The answer is nothing; our sinful nature runs too deeply. We cannot save ourselves. We need a redeemer.
Speaking of other world religions, they tend to be mankind’s attempt to overcome sin and nullify the consequences of sin. For instance, Islam attempts to overcome the effects of sin by adherence to the five pillars of their faith, which are the five things one must do in order to assure going to heaven. In the 2000 years of Christians history, we have also been guilty of this same sort of heresy. We Christians know this as “works-righteousness.” Many Christians today are still guilty of this heresy, either knowingly or subliminally.
But if religion is man’s attempt to do something to be right with God and overcome the consequences of sin, then Biblical Christianity is not a religion at all. We aren’t overcoming anything. What needs to be done has already been done, and we didn’t do it. The work that needed to be done was done 2000 years ago by God Himself, Jesus the Messiah, at His Cross and Resurrection. All we do, like Abraham, is accept the gift of grace, answer the invitation, trust God, and enter a salvific relationship with Him. We are saved by God’s grace though our faith-relationship with Christ. In this sense, Christianity is not a religion, it is a relationship.
Therefore Genesis 15:6 takes us to the heart of the Gospel- "[Abram] believed the LORD; and the LORD reckoned it to him as righteousness. St. Paul clarifies this in Rom 3:23-24, “… for all have sinned and fall short of the glory of God, and are justified by grace as a gift, through the redemption that is in Christ Jesus…” Abraham was not any better or righteous than you or I. In fact, the story of Abraham reveals Him to be a bit a scoundrel. His grandson, Jacob, another OT Patriarch, was a deceiver and trickster who became a man of faith. God thus claimed him as His own, set him apart, and made him into something new. Like us, the Patriarchs fall short of the Glory of God, but what they did do was submit to God in faith, belief, and trust. It was credited it to them as righteousness. So it is to be with us!
Fr. Rob Hartley, Lent 2, 2019