Atonement, at-one-ment, God "meant" for us to be "at one" with Him.
Sin caused a separation between us & God. But God did not separate Himself from us. Sin deceives us into thinking that God's love for us is conditional thus making us feel separated from Him. Jesus crushed that lie with the truth, by showing His unconditional love for us by dying for us to give us life & remove sin's power over our minds & our spirits.
Our Father loved us before we were ever born, before we could possibly meet any conditions. Before we could think or breathe His love abounded for us & His love continues to abound for us forever. Separations be gone! Lies be gone! We are at one with You God!