Let us not grow weary: Avoid letting sinful behavior sneak in or relying on strict rules instead of following the Spirit (5:25).
for in due time we will reap a harvest: This promise encourages Christians to keep doing good work (see Romans 8:28).
if we do not give up: God's promises to believers require them to keep their faith strong (see also Luke 18:1; 2 Corinthians 4:1).