Stephen is telling his accusers and judges (the Sanhedrin) the history that they and he shared…God working in and through their ancestor, Abraham.
(NASB) Acts 7:5 “But He (God) gave him (Abraham) no inheritance in it (the land of Israel), not even a foot of ground, and yet, even when he had no child, He promised that He would give it to him as a possession, and to his descendants after him.”

  God grows your faith and mine as we call out to Him during the times of waiting.
  The living God of the Holy Bible grew Abraham’s faith in possessing the land to which God called him.

  The Lord God’s promises are always fulfilled in His timing.  His promises are always fulfilled for His purposes.
  And in the meantime, we are not to take circumstances into our own hands to fulfill God’s promises. 
(That is what Abraham and Sarah did before Isaac was born – Genesis 16)
  But the Lord God did not give up His purposes for Abraham and his descendants.

  What are we not to do when God’s word tells us to wait? 
Willfully force the circumstances to bring about our perception of God’s will and timing.
We are only exposing our demanding, selfish ways, our “rights”.
  What are we to do when God’s word tells us to wait?
Literally place our trust in Him, the living God of the Bible (He is the same God in the Old Testament and the New Testament!).

(NASB) Proverbs 3:5-6 “Trust in the Lord with all your heart
And do not lean on your own understanding.
6 In all your ways acknowledge Him,
And He will make your paths straight.”

  Today, we are to live by trusting God and His words. 
To wait for God’s timing, when we live by faith, God knows what He is doing!

Today, we are not to lean on our limited, short-sighted, and
selfish understanding.

  Today, in all of our ways, in all of our circumstances we are to agree with God and acknowledge that He is on top of things in our lives… and what He chooses for me is a straight path to Him!

~ Take it to heart ~

Live by faith in the Lord Jesus Christ and the promises of God…
wait on the Lord.

(NASB) Psalm 25:5
“Lead me in Your truth and teach me,
For you are the God of my salvation;
For You I wait all the day.”