We have the Promise of Abraham, because of Jesus.
In fact, throughout the Gospels, we find a number of promises from Jesus to all of us:
"Fear not, little flock; for it is your Father's good pleasure to give you the kingdom." (Luke 12: 32)
"The thief cometh not, but for to steal, and to kill, and to destroy: I am come that they might have life, and that they might have it more abundantly." (John 10: 10)
"I will not leave you comfortless: I will come to you." (John 14: 18)
Paul writes that Abraham never wavered about God's promise to him:
"He staggered not at the promise of God through unbelief; but was strong in faith, giving glory to God;" (Romans 4: 20)
What else do we receive in these promises?
"Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust." (2 Peter 1: 4)
We also have this wonderful promise because of all that Jesus has done for us as is for us today!
"5Let your conversation be without covetousness; and be content with such things as ye have: for he hath said, I will never leave thee, nor forsake thee.
"6So that we may boldly say, The Lord is my helper, and I will not fear what man shall do unto me." (Hebrews 13: 5-6)
All of these promises, of course, are wrapped up in the Promise of His Spirit:
"And, being assembled together with them, commanded them that they should not depart from Jerusalem, but wait for the promise of the Father, which, saith he, ye have heard of me." (Acts 1: 4)
"1And when the day of Pentecost was fully come, they were all with one accord in one place. 2And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting. 3And there appeared unto them cloven tongues like as of fire, and it sat upon each of them. 4And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance." (Acts 2: 1-4)
Christ promised you the promise of His Father, and you never have to wonder if He will fulfill every promise which He offered, for all was fulfilled at the Cross.