Romans 4:19 And not being weak in faith, he did not consider his own body, already dead (since he was about a hundred years old), and the deadness of Sarah’s womb.
Abraham exercised his faith: he knew his body was beyond an age where he would be able to have children, but he continued to trust in what God had promised.
We need to put aside our earthly shortcomings and limitations because God is not limited by our physical earth as we are.
Give God your doubt so He can show you what is possible when you place your faith and trust in His hands instead of your own hands!