If I accept that God or gods exist, how do I choose? Don’t all religions believe essentially the same things?

Actually, no. Attempts to make all religions “basically the same” involve the serious problem of reductionism, reducing everything to a broad common denominator. All religions can be false but they cannot all be true. Analogies such as the "mountain analogy" of many paths up the same mountain of truth obscure the real and crucial differences between world religions. For example: 

Buddhism denies, but Christianity affirms existence of a personal God.

Judaism confuses, but Christianity confirms life after death.

Radical Islam endorses killing of infidels, Christianity teaches love of enemies. 

On the assumption that the New Testament of the Bible is an historically accurate document (a claim we will soon address), it is clear from the testimony of many eyewitnesses, that Jesus Christ was much more than an ordinary human being. He was indeed, as he claimed to be on numerous occasions, the unique Son of God. These ‘blasphemous’ claims led to his crucifixion.

[i] Jesus Christ claimed to be the only way to God. 

[ii] Jesus Christ confirmed his claim and unique status by rising from the dead.

[iii] No other religious leader has risen from the dead.

[iv] Therefore, Jesus Christ is the only way to God. 

In a pluralistic and ‘tolerant’ age this will strike many as unacceptable arrogance. How should we respond to this astonishing claim? Jesus Christ’s claim gives us just three alternatives: he was a liar, he was a lunatic, or he was the Lord he claimed to be. C.S. Lewis had this to say: