“In hope of eternal life, which God, that cannot lie, promised before the world began;”  
Titus 1:2

The Bible says:
“Love never fails…”  1 Corinthians 13:8, ISV
And:
“Now this hope does not disappoint us, because God’s love has been poured out into our hearts by the Holy Spirit, who has been given to us.”  Romans 5:5, ISV
That means, it is in us to succeed, nobody can take it out!
He had said:
“Beloved, I wish above all things that thou mayest prosper and be in health, even as thy soul prospereth.”  3 John 1:2
And by himself, he put in us that which will make his highest wish come through.
When we got born again, the Bible says:
“how that God was in Christ—a world reconciling to Himself, not reckoning to them their trespasses; and having put in us the word of the reconciliation,”  2 Corinthians 5:19, YLT
So the gospel was committed unto us; it is inside us! God has made us successful ministers of the gospel; gone are the days you had to be concerned about your ability to preach! He put the word of reconciliation within you and made you a success for life:
“Who also hath made us able ministers of the new testament; not of the letter, but of the spirit: for the letter killeth, but the spirit giveth life.”  2 Corinthians 3:6