One argument atheists present against God is that we can't see God or sufficient evidence of God's presence.

For Christians, it can be a challenge for our faith that God is unseen. Why does He not make Himself readily apparent and present to us?

Job 13:20-28; 37:23
Psalm 10:1; 13:1; 44:1-26; 88:1; 89:46; 143:1-8
Psalm 42:1-11; 63:1-2 As a deer pants for the water brooks… Hoping in God while feeling forgotten by God.

Living By Faith

2 Corinthians 4:18
2 Corinthians 5:7 We walk by faith, not sight.
Hebrews 11:1,6
1 Peter 1:3-12

Miracles Are of Limited Value

Much as we would like to see miracles to affirm God's power and presence, they may not be as transformative to us as we would like.

Deuteronomy 4:32-40; 5:23-33 Consider the history of Israel, all the miracles they saw, and yet their limited capacity to understand, love and obey God.
1 Kings 19:11-13 God showed some miraculous signs to Elijah, but God was present in the still, small voice.
Psalm 95:7-11 quoted in Hebrews 3:7-19. Today, if you will hear His voice: “Do not harden your hearts, as in the rebellion, As in the day of trial in the wilderness, When your fathers tested Me;

Evidence May Already Be Sufficient

It may be that the evidence is amply sufficient for us to believe. But we need to have a heart to recognise it and accept it.

Psalm 19
Psalm 148
Jeremiah 33:25 God's creation shows His character.
Matthew 12:38-42; Luke 11:29-32 Jesus criticised the Jews of His day for asking for a sign. Apparently they had plenty enough signs, but weren't willing to see them for what they were.
Matthew 16:1-4
Mark 8:11-12
Luke 11:16
John 2:18
John 4:48
John 6:30-31 They wanted to see Jesus miraculously produce bread. He told them, "I am the bread from heaven."
John 15:27; 19:35; 20:30-31; 21:24-25
John 20:26-31 Jesus said to Thomas, "Blessed are those who have not seen, and yet have believed." This indicates to us that we should be able to believe in Jesus on the basis of the Biblical witnesses.
Romans 1:18-23

This Era is of God Deliberately Hiding Himself and Veiling the Truth

Proverbs 25:2 It is the glory of God to conceal a matter, but the glory of kings to search out a matter.
Ecclesiastes 3:11 Also He has put eternity in their hearts, except that no one can find out the work that God does from beginning to end.
Ecclesiastes 8:11
Matthew 11:25; Luke 10:21
Mark 4:11-12
John 12:35-41

Jesus Sometimes Hid His Ministry

Matthew 8:1-4; Mark 1:40-45 Jesus healed a leper, and told him not to tell anyone. But he spread the word freely, so Jesus couldn't go into cities.
Matthew 9:27-31 Jesus healed two blind men. He told them not to spread the news, but they did.
Matthew 12:15-21
Mark 3:12 Jesus commanded unclean spirits not to say who He was.
Mark 5:43 Jesus restored a girl to life, then told them to keep it quiet.
Mark 7:24-30 Jesus wanted to be hidden in Tyre, but was unsuccessful. A Greek woman begged him to heal her daughter.
Mark 7:31-37 Jesus healed a deaf mute, and commanded him not to spread the word. But people did.
Mark 8:11-12 Jesus refused to give a sign for the Pharisees.
Mark 8:22-26 Jesus healed a blind man.
Mark 8:27-30 Jesus told His disciples not to spread the word that He was the Christ.
Mark 9:1-10 Transfiguration. He told them not to tell anyone, until after He was resurrected.

God Has Revealed Things to Chosen People

Matthew 11:25-26; Luke 10:21-24
John 6:44 No one can come to Christ unless the Father draws them.
1 Corinthians 1:26-31 Not many wise, mighty, noble are called.
1 Corinthians 2:6-16 The Holy Spirit enables understanding of the things of God, to those who are given it.
1 Peter 1:10-12

This Era is of Satan Ruling the World

John 12:31; 14:30; 16:11 Jesus talked about the "ruler of this world" who is in opposition to God, and soon will be judged.
2 Corinthians 4:3-4 The "god of this age" blinds people to the truth and the gospel.
Ephesians 2:1-3 The course of this world is led by the prince of the power of the air, the spirit who now works in the sons of disobedience.
Ephesians 6:10-12 We must put on the armour of God, to resist the devil, and principalities, powers, rulers of the darkness of this age, spiritual hosts of wickedness in the heavenly places.

Our Sins Cause a Separation From God

Genesis 3:21-24 After Adam's and Eve's sin, they were no longer able to be in God's presence, and lost access to the tree of life. Adam and Eve's choice to eat from the other tree is representative of our desire to "go our own way" and make our own choices, rather than trusting God. This requires a time in which we are free to make our own choices without intervention from God.
Deuteronomy 32:19-38 God hid Himself from Israel due to their persistent disobedience and idolatry.
Proverbs 15:29 God is far from the wicked, but hears the prayers of the righteous.
Isaiah 50:1 God compares His people to a divorced wife.
Isaiah 59:1-15 Your iniquities have separated you from your God.
Jeremiah 5:25 Your sins have withheld good from you.
Ezekiel 39:21-24 The Gentiles shall know that the house of Israel went into captivity for their iniquity.
3 John 1:11 He who does evil has not seen God.

God Sees How We Live In His Absence

Job 42:1-6 Job thought he knew God, but came to see that he had an insufficient concept of God's greatness.
Ecclesiastes 8:11
Matthew 24:45-51 Consider the servant who says "My master delays his coming" and does wickedly.
1 John 4:20-21 If we don't love our brother whom we see, how can we love God whom we don't see?

Patience

Matthew 10:22; 24:13,46; Mark 13:13 He who endures to the end will be saved.
Luke 8:15 Bear fruit of righteousness with patience.
James 1:2-4 The testing of your faith produces patience and other virtues.
Revelation 21:7

Learn to Trust God's Character and Promises

Luke 11:5-8 Parable of friend at midnight.
Luke 18:1-8 Parable of the persistent widow.

God Wants Us to Seek Him

1 Chronicles 28:9
Psalms 9:10
Psalm 119:2,10
Proverbs 2:1-9; 8:17 Seek and find wisdom.
Isaiah 55:6 Seek God while He may be found.
Jeremiah 29:12-13
Matthew 5:6 Hunger and thirst for righteousness.
Matthew 7:7-11; Luke 11:9-13 Ask, seek, knock.
Mark 4:24-25 The measure you use will be the measure you receive.
Acts 17:22-31 God hopes that we might grope for Him and find Him — He is not too far from us.
Hebrews 11:6 Approach God with faith.
James 1:5 Ask God for wisdom.
James 4:8 Draw near to God, and He will draw near to you.

Know God Through Creation

Psalm 8:1-9
Psalm 75:1
Psalm 111:2
Psalm 113:4
Psalm 139:13-18
Psalm 148
Jeremiah 33:25
Romans 1:18-25

Know God Through His Holy Word

Isaiah 8:20
John 17:17
Acts 24:14
2 Timothy 3:14-17
Hebrews 4:12

Know God Through His Moral Law

Joshua 1:8
Psalm 19:8-11
Psalm 119
Matthew 5:6
Matthew 22:34-40 Greatest commandments: love God and neighbour.
John 14:15,21,23-24 We love God and know God by keeping His commandments. Father and Son make their home with such a person.
John 15:9-17
Romans 7:7-12
Romans 13:8-14
1 John 2:3-6,29; 5:1-3

Know God by Discerning His Character

Exodus 34:5-8
Jeremiah 9:23-24
1 Peter 1:8

Know God Through Jesus Christ

Matthew 11:25-30
John 1:4-18; 3:19; 8:12; 9:5 Jesus is the light who shines in the darkness.
John 14:7-11 If we've seen Christ, we've seen the Father.
John 15:1-8 Christ is the vine, we are the branches.
2 Corinthians 4:4-6
Colossians 1:15
Hebrews 1:1-4

Know God Through His Spirit

Jeremiah 31:33-34 The Holy Spirit in the New Covenant enables people to know God.
Luke 11:9-13 Ask, seek, knock for God's Holy Spirit.
John 1:13; 3:3-8 We must be reborn of the Spirit.
John 14:15-31 In v.22, Judas asks "Lord, how is it that You will manifest Yourself to us, and not to the world?" In v.15,21,23-24 Jesus says we love God and know God by keeping His commandments. Father and Son make their home with such a person. Father and Son interact with those born of the Spirit, through the Spirit.
John 16:7-15
Romans 8:1-17 If we live by the Spirit rather than by the flesh, we become children of God.
1 Corinthians 2:10-16

Holy Spirit Could Come After Christ Left

John 16:7-15 Jesus Christ returning to heaven may seem like a step backwards. But Jesus Christ said it is better for us.

We Will See God When Sin is Removed

Jeremiah 31:33-34
Matthew 5:8
1 Corinthians 13:12
2 Corinthians 6:14-18; 7:1
Hebrews 12:14
Revelation 21:1-8
Revelation 22:1-5,14