But without faith (a firm persuasion or conviction) it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.  Hebrews 11:6

• God is revealed in creation:

The heavens declare the glory of God; and the firmament sheweth his handywork.  Psalm 19:1

For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse:  Romans 1:20

• God’s laws are written upon man’s heart and conscience:

For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves:

Which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another;  Romans 2:14 & 15

• God is unveiled in Jesus Christ:   

Beware lest any man spoil you through philosophy and vain deceit, after the tradition of men, after the rudiments of the world, and not after Christ.  For in him dwelleth all the fulness of the Godhead bodily.  Colossians 2:8 & 9

And this is life eternal, that they might know thee the only true God and Jesus Christ, whom thou hast sent.  John 17:3.

• God is revealed in a changed life:

Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new.  II Corinthians 5:17

Know ye not that the unrighteous shall not inherit the kingdom of God?  Be not deceived: neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor abusers of themselves with mankind,

Nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners, shall inherit the kingdom of God.

And such were some of you: but ye are washed, but ye are sanctified, but ye are justified in the name of the Lord Jesus, and by the Spirit of our God.  I Corinthians 6:9, 10 & 11

Come and hear, all ye that fear God, and I will declare what he hath done for my soul.  Psalm 66:16