Biblical definition: Faith

Hebrews 11

1 Now faith is the substance of things hoped for, the evidence of things not seen.

2 For by it the elders obtained approval.

3 Through faith we understand that the worlds (eternities) were framed by the word1 of God,
so that things which are seen were not made of things which do appear.

6 But without faith it is impossible to please him:
for he that comes to God must believe that he is,
and that he is a rewarder of them that diligently seek him.

1 Greek: ρήματι (rhēma, here in dative case): Word spoken through the living voice

Psalms 33 (Extract)

1 Rejoice in the LORD, O you righteous: for praise is fitting for the upright.

2 Praise the LORD with harp: sing unto him with the psaltery and an instrument of ten strings.

3 Sing unto him a new song; play skillfully with a loud noise.

4 For the word of the LORD is right; and all his works are done in truth.

5 He loves righteousness and justice: the earth is full of the goodness of the LORD.

6 By the word of the LORD were the heavens made; and all the host of them by the breath of his mouth.

7 He gathers the waters of the sea together as a heap: He lays up the depth in storehouses.

8 Let all the earth fear the LORD: let all the inhabitants of the world stand in awe of Him.

9 For He spoke, and it was done; He commanded, and it stood fast.

1 Thessalonians 2

13 For this cause also thank we God without ceasing, because,
when you received the word of God which you heard of us,
you received it not as the word of men, but as it is in truth, the word of God,
which effectually works also in you that believe.