Instead, he had to address them as infants, as those who had failed to mature properly in their walk with Christ. But they were not doing that. God's plan is birth, growth, and maturity. We recognize this immediately in the physical world He has created. The plants grow and mature and provide oxygen and food.
Animals grow and mature and provide food and clothing.
People, likewise grow, develop, and mature. This was even true of Christ. Jesus was God in flesh. The purpose the Father had sent Him to accomplish. He redeemed for Himself those whom the Father had elected into salvation.