Romans 4:20-21

Be he did not doubt or waver in unbelief concerning the promise of God, but he grew strong and empowered by faith, giving glory to God, being fully convinced and empowered by faith, giving glory to God. 

Abraham didn’t doubt or fear that God wouldn’t do what He promised. The bible says perfect love casts out all fear! When we keep ourselves in Love towards one another and cast down imaginations of fear and doubt, we will succeed. Our lives matter to God, and He is willing and able to keep His promises.