The Spirit serves as both God's promise of future blessings and a preview of eternal life and power. A believer's eternal inheritance includes everything God promised (see also 1:18; Romans 8:17; 2 Corinthians 1:22; 5:5; Galatians 3:29; 4:7; Colossians 1:12; 3:24; Titus 3:7).