The saving work of Christ on the Cross for the sins of humanity which was efficacious. Efficacious means the perfectly innocent Christ in His humanity, sacrificed Himself and was totally acceptable to God. Christ died in our place. He paid in full, our insurmountable debt. Christ redeemed us — Romans 3:24-26; 1 Corinthians 1:30; 6:20; 7:23; Galatians 1:24; 2:20; 4:4; Ephesians 1:7; 5:2; Colossians 1:14, 20-22; 1 Timothy 2:6; Titus 2:14; Hebrews 9:12-15; 1 Peter 1:18-19; Revelation 5:9-10; Hebrews 9:26; 10:5-10.
Animal sacrifices in the Old Testament were accepted by God to make temporary atonement for sin, but have no efficacy (Hebrew 10:4). Atonement is reconciliation between God and man. Christ propitiated (satisfied) God and removed the barrier between God and man (Reconciled). Unlimited Atonement is eternal for the believer. Christ died once, for all, for all time (2 Corinthians 5:18-21; Ephesians 2:15-18; Colossians 1:20-22). Salvation is available to all — to anyone who will call upon the name of the Lord (Acts 16:31).