1 John 5:15

and since we are sure that he hears all our prayers, we are sure that the petitions we presented to him, will be answered.

Mark 11:24

therefore whenever you pray, be fully persuaded of obtaining your request, and I assure you it shall be granted, whatever it be.

Luke 11:9-10

I tell you likewise, ask, and it shall be given: seek, and ye shall find: knock, and the door shall be opened.

1 John 5:18-20

we know that a true christian will not commit such a sin, for he that is the child of God keeps upon his guard, so that the wicked spirit does not approach him.

Treasury of Scripture Knowledge

Summary

And if we know that he hear us, whatsoever we ask, we know that we have the petitions that we desired of him.

General references

Bible References

We know

Mark 11:24
therefore whenever you pray, be fully persuaded of obtaining your request, and I assure you it shall be granted, whatever it be.
Luke 11:9
I tell you likewise, ask, and it shall be given: seek, and ye shall find: knock, and the door shall be opened.

General references

Matthew 21:22
and whatever ye shall ask in prayer, with faith, ye shall receive.